具有出生率密度制约的非自治SIRS模型

研究了一类具有出生率密度制约的非自治SIRS模型,获得了疾病持续和绝灭的阈值R*和R*,证明了当R*>1的时候疾病将持续存在;当R*<1的时候疾病将会消亡,最后利用Lyapunov泛函方法得到系统全局吸引的一些条件.     

近代五邑侨乡口供纸探究

“口供纸”是起源于美国排华时期的一种移民资料,其使用一直延续到20世纪中期。它集中出现在有“美国华侨之乡”称谓的五邑侨乡,其中台山、开平最多。口供纸的运用是一个特殊时期的一种特殊国际移民形式。口供纸产生的背景和类型、制作方式独具特点,国内的华侨历史研究对此注意很少。     

社会生产方式与生育文化变迁研究

以中国传统生育文化的生成土壤为基础,将中国生育文化作为一个包括技术系统、社会系统和意识形态系统的整体动力系统,并把社会生产方式作为推动这一系统运行、变迁的动力源泉,由此探讨生产力和生产关系的矛盾运动对中国生育文化的形成、发展、变迁的决定作用,以及这种作用的内在机理和外部表现形式,并揭示存在各种不同社会机体中生育文化发展、变迁的特殊规律,以正确把握由传统生育文化向现代化生育文化转变的内在动力和运行机制。     

崔致远出生年份及其及第年龄再考论

针对崔致远的出生年份及其及第年龄这一问题,尤其是对“857年出生、18岁及第说”和“855年出生、20岁及第说”的各种论点和症结进行了再考论。对于“857年出生、18岁及第说”,虽然不少的后世文献记录都为其提供了根据,但它与崔致远自述中所说“在唐生活了18年”这一事实并不相符,这是决定性的一点。反之,“855年出生、20岁及第说”虽与后世文献的一些记录不相符,但基本上能与崔致远的自述相吻合,然而还需要通过对当时的制度或某些词汇的解释进行补充说明。两种说法虽然都存在一些症结或疑问,但从对这些问题的解释上来看,“855年出生说”比“857年出生说”更具有合理性。     

陶宗仪生年和早年求学新考

元末明初儒士陶宗仪的生平情况,见于其友人孙作《陶先生小传》、《明史.文苑传》、贝阙《南村外史传》、邵亨贞《南村辍耕录疏》等,然对其生年和早年求学情况,现存文献大多语焉不详。由于其墓志铭和行状未能保存下来,故而学术界对其生平多有争议。现据陶宗仪老师钱璧《元钱伯全札》、友人孙作《陶先生小传》、邵亨贞《南村草堂记》、同乡林克贤《南村辍耕录后叙》等文献,结合《南村辍耕录》等资料,考订其生年及从钱璧问学等情况。     

Solving sport’s ‘relative age’ problem: a systematic review of proposed solutions

ABSTRACT

Though the existence of Relative Age Effects (RAEs) has been documented through a multitude of studies spanning various sports and levels of play, application of solutions related to RAEs has been limited. In this review, the strengths and weaknesses of various proposed solutions to RAEs in youth sport are considered. Our objective was to identify, collate, and disseminate a comprehensive list of solutions related to the prevalence of RAEs in youth sport. English language, peer-reviewed articles were searched using the SPORTDiscuss database. Keywords ‘relative age’, ‘relative age effect*’, and sport* were used to locate research articles. The inclusion criteria were the following: (1) publication date between January 1980 and December 2018; (2) solutions were suggested related to RAEs. Sixty-three peer-reviewed publications contained proposed solutions to RAEs. Many solutions have been proposed to address RAEs in sport. Most are theoretical and there has been no attempt to implement them. Future research should test possible proposed solutions to RAEs in sport. However, implementing these solutions has the potential to both positively and negatively affect career and life outcomes for those athletes involved. Therefore, it is important to be cautious in how these possible solutions are tested.     

羔羊生后24小时内血液某些免疫功能指标变化特点

选用１２只自然分娩、初生重１．５—４．５ｋｇ的新生湖羊羔为对象,研究了生后２４ｈ内血液某些免疫功能指标变化特点。结果表明：羔羊生后２４ｈ内ＷＢＣ明显升高;中性粒细胞（％）生后１ｈ较低,８ｈ内明显升高,以后相对稳定,淋巴细胞和单核细胞（％）与中性粒细胞呈相反关系变化,淋巴细胞中Ｂ淋巴细胞比例１２ｈ内明显上升,以后下降,Ｔ淋巴细胞比例变化与其相反;血浆ＴＰ、Ａ、Ｇ、ｒ—Ｇ含量在生后１ｈ均较低,８ｈ吃初乳后明显升高,以后ＴＰ保持相对稳定的高水平,Ａ呈下降趋势,Ｇ特别是ｒ－Ｇ进一步上升。     

环境与优生

文章主要分析了环境因素,如化学、物理、生物、行为和营养等因素对优生的影响。提出改善优生环境的措施及设想,以此消除危害优生的各种环境因素,预防和减少出生缺陷儿的出生,达到优生目的,提高人口素质。     

屈原生卒年考证

关于屈原生卒年,目前盛行“生于公元前340年,卒于公元前278年,享年62岁”的郭沫若说,笔者认为有误。笔者从屈原作品中重新推算,得出的结论为：生年为楚宣王二十七年,公元前343年,为戊寅年,卒年为顷襄王二十二年,享年六十六岁。     

Date of birth and achievement in GCSE and GCE A‐level

General Certificate of Secondary Education (GCSE) examinations are taken by almost all pupils in England, Wales and Northern Ireland at age 16 years. General Certificate of Education Advanced level (GCE A‐level) examinations are normally taken by relatively able students at age 18. The effect of month of birth on attainment in these public examinations is investigated through a database which brings together the 1991 GCSE results and the 1993 GCE A‐level results of all candidates born between September 1974 and August 1975. Older pupils perform best at GCSE but not at GCE A‐level. Selection effects on entry to A‐level courses appear to explain why this is the case.