自学单元程序教材介绍:化学键(二)     

Iain M.Duncan  黄经昌 《化学教学》1982,(4)

伸展在晶格内的离子键很强,因此从晶格中移走离子是困难的。由于这个原因,离子型化合物具有较高的熔点和沸点。存在于共价型固体或液体中的分子间的作用力没有这样强(除1～2例外),使分子聚集在一起的作用力布遍于固体中也是不强的。考虑下列的气化热:  相似文献   

Diversity of Gram negative bacteria antagonistic against major pathogens of rice from rice seed in the tropic environment   总被引：2，自引：0，他引：2  

谢关林  SOAD Algam  SWINGS J  MEW T.W 《Journal of Zhejiang University. Science. B》2003,(4)

INTRODUCTIONRiceseedharborsadozenofplantpathogen icbacteria (Gotoetal.,1 988;Xieetal.,1 998) .Thebacterialpathogenscausearangeofricediseases,someverydestructivewhileothershavenoeffectonricecropgrowth .Inthisstudy ,wefoundalargenumberofbacteriaasso ciatedw…  相似文献   

Access to postsecondary education through sign language interpreting   总被引：1，自引：0，他引：1  

Marschark M  Sapere P  Convertino C  Seewagen R 《Journal of deaf studies and deaf education》2005,10(1):38-50

Despite the importance of sign language interpreting for many deaf students, there is surprisingly little research concerning its effectiveness in the classroom. The limited research in this area is reviewed, and a new study is presented that included 23 interpreters, 105 deaf students, and 22 hearing students. Students saw two interpreted university-level lectures, each preceded by a test of prior content knowledge and followed by a post-lecture assessment of learning. A variety of demographic and qualitative data also were collected. Variables of primary interest included the effects of a match or mismatch between student interpreting preferences (interpreting vs. transliteration) and the actual mode of interpreting, student-interpreter familiarity, and interpreter experience. Results clarify previous contradictory findings concerning the importance of student interpreting preferences and extend earlier studies indicating that deaf students acquire less than hearing peers from interpreted college-level lectures. Issues relating to access and success in integrated academic settings are discussed as they relate to relations among student characteristics, interpreter characteristics, and educational settings.  相似文献   

我们在教书中育人     

M.B.чортковская  陈一新 《职教译丛》2001,(3):14-15

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Postpartum depression, marital dysfunction, and infant outcome: a longitudinal study          下载免费PDF全文

Roux G  Anderson C  Roan C 《The Journal of perinatal education》2002,11(4):25-36

This longitudinal study explores the relationship of postpartum depression (PPD) and marital dysfunction on infant outcomes from birth to 2 1/2 years of age among middle-class, postpartum women. Participants were recruited during the prenatal period. Twelve mothers completed the study throughout a 2 1/2-year period. Questionnaires, semistructured interviews, and observations were used to collect data. Content analysis of the interviews (Morse & Field, 1995) was conducted and thematic patterns were identified. Clinical PPD and marital dysfunction (defined as little or no support or closeness, or verbal, emotional or physical abuse) characterized nearly one in three mothers. Four themes describing the women's postpartum progression were identified: stress, isolation, resentment, and eventual adjustment by creating a new normal. No major developmental delays or behavioral problems were found among the infants. Eight of the 12 mothers who were initially identified as breastfeeding nursed their infants for 6-18 months. Regardless of financial and educational advantages, mothers in the study experienced depression and marital dysfunction. These findings support other studies that confirm the lack of association of PPD with social class or marital status. Childbirth educators and other health care professionals are encouraged to continue providing expectant families with anticipatory education and community resources in order to increase awareness of mental health and marital risks during the postpartum transition.  相似文献   

US approves gene therapy on humans     

Joyce C 《New scientist (1971)》1985,108(1476):19

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Parameters in television captioning for deaf and hard-of-hearing adults: effects of caption rate versus text reduction on comprehension     

Burnham D  Leigh G  Noble W  Jones C  Tyler M  Grebennikov L  Varley A 《Journal of deaf studies and deaf education》2008,13(3):391-404

Caption rate and text reduction are factors that appear to affect the comprehension of captions by people who are deaf or hard of hearing. These 2 factors are confounded in everyday captioning; rate (in words per minute) is slowed by text reduction. In this study, caption rate and text reduction were manipulated independently in 2 experiments to assess any differential effects and possible benefits for comprehension by deaf and hard-of-hearing adults. Volunteers for the study included adults with a range of reading levels, self-reported hearing status, and different communication and language preferences. Results indicate that caption rate (at 130, 180, 230 words per minute) and text reduction (at 84%, 92%, and 100% original text) have different effects for different adult users, depending on hearing status, age, and reading level. In particular, reading level emerges as a dominant factor: more proficient readers show better comprehension than poor readers and are better able to benefit from caption rate and, to some extent, text reduction modifications.  相似文献   

西德尼.哈里斯漫画     

西德尼.哈里斯 《科学启蒙》2001,(4)

砂秘辱如.诬西德尼.哈里斯漫画@西德尼.哈里斯~~  相似文献   

我的科学经历     

格林.T.西博格 《中学生数理化》2004,(9)

回想起来,在我成长过程中,既有与众不同的地方,也有许多很平凡的地方。在上高中以前,我完全没有机会接触科学,对于科学的作用几乎一无所知。就是上高中以后,我的主要精力  相似文献   

Gesture as a window on children's beginning understanding of false belief     

Carlson SM  Wong A  Lemke M  Cosser C 《Child development》2005,76(1):73-86

Given that gestures may provide access to transitions in cognitive development, preschoolers' performance on standard tasks was compared with their performance on a new gesture false belief task. Experiment 1 confirmed that children (N=45, M age=54 months) responded consistently on two gesture tasks and that there is dramatic improvement on both the gesture false belief task and a standard task from ages 3 to 5. In 2 subsequent experiments focusing on children in transition with respect to understanding false beliefs (Ns=34 and 70, M age=48 months), there was a significant advantage of gesture over standard and novel verbal-response tasks. Iconic gesture may facilitate reasoning about opaque mental states in children who are rapidly developing concepts of mind.  相似文献