检索结果-南通市图书馆

维普期刊数据库

东海带鱼春、夏和秋季产卵群体的生殖周期特性与种群问题

在线全文

学校读者我要写书评

暂无评论

动物学报 1985年第4期34卷 348-358页

作者：罗秉征卢继武黄颂芳中国科学院海洋研究所

东海带鱼有春、夏和秋季生殖之别,秋季并出现分群现象。带鱼第一个生殖周期与其出生季节相适应;从第二个生殖周期开始则消失了与出生季节的相应关系。根据种群结构的组成特性以及耳石相对生长的分析,从种群概念上阐明了不同季节出生的... 详细信息

东海带鱼有春、夏和秋季生殖之别,秋季并出现分群现象。带鱼第一个生殖周期与其出生季节相适应;从第二个生殖周期开始则消失了与出生季节的相应关系。根据种群结构的组成特性以及耳石相对生长的分析,从种群概念上阐明了不同季节出生的带鱼群体的相互关系。论证了春、夏和秋季产卵群体系为同一种群的不同生物学群。文中讨论了种下阶元的不同分化程度和位置:繁殖群(种群)——繁殖下群——生物学群。

关键词： Trichiurus haumela Spring-summer and autumn spawning population.

维普期刊数据库

HIVIAIDS as a Current Demographic Security Problem

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering(A) 2013年第6期2卷 381-387页

作者： Peter Cajka Department of lnternational Relations and Diplomacy Faculty of Political Science and International Relations Matej Bel UniversityBansk6 Bystrica 97401 Slovak Republic

The development of the society depends on a number of factors. In the past, major changes were mainly driven by significant discoveries, mass diseases, disasters and wars. The second half of the 20th century brings new global challenges and problems when need to States, international community, individuals must react. These are problems which must respond to all global players, because it is problems whose solution is only possible through the global efforts and concerns of the whole of humanity. The issue of AIDS/HIV is one of them.

关键词： HIV/AIDS migration population.

Biological Status of Indus River Dolphin （Platanista Minor Owen） in Indus River, Northern Pakistan

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Life Sciences 2011年第1期5卷 39-47页

作者： Farzana Perveen Sardar Azher Mehmood Shabbir Ahmed Zia Ur Reman Department of Zoology Hazara University Garden Campus Mansehra-21300 Pakistan

A study was aimed to determine the biological status of the Indus river dolphin, Platanista minor Owen in Indus river with respect to distribution, threats and protection throughout its range in Northern Pakistan. For this purpose, a survey was conducted in an area of 103.5 km including the Indus river and its tributaries in March 2009 for estimating its distribution and population.size using both direct observations of the dolphin as well as indirect evidences from its signs. The best group size was estimated with an abundance of 54 dolphins. Approximately 53.7% （1.07 dolphin＆m） of the dolphin-population.occurred in 27 km from Miran onward to Ramak, however, 38.9% （0.46 dolphin/km） occurred in 46 km from Dera Ismail （D.I.） Khan bridge to Miran, moreover, 7.4% （0.13 dolphin/kin） occurred in 30.5 km from Saggu, near Meetapur-village to D.I. Khan bridge in the Indus river. The highest density was found between Miran and Ramk. A pronounced increase in dolphin encounter rate and abundance were observed in a downstream-direction. Threats to dolphins include too much vessel-traffic, disturbance by the crane, duck-hunters, and no effective-protection. Dolphins are particularly vulnerable to the high levels of anthropogenic activities because of their restricted habitat. Threats vary geographically in their importance, but generally include accidental killing during fishing-operations, habitat-loss and population.fragmentation from water development. Deliberate killing for dolphin products also threatens the dolphins. Potential for protections and possibilities for dolphin eco-tourism measures must be taken.

关键词： Dolphin endangered or critically endangered Indus river Northern Pakistan protection population.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A SOCIAL CRISIS

The World of Chinese 2022年第2期 42-47页

作者： PEIXUAN XIE VCG

Started in the 1980 s to tackle problems created by urbanization,the field of social work is set to play a big role in serving China’s aging *** without autonomy from the government or access to the most marginalized... 详细信息

关键词： population. difference. autonomy

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

HEARTH WARMING

The World of Chinese 2020年第2期 74-76,M0002页

作者： SUN JIAHUI 不详

Every winter,China faces the mammoth challenge of heating the world’s biggest *** kang beds,to energy-efficient coal bricks,to the government’s decision to centrally heat only northern China in the 1950s,we look bac... 详细信息

关键词： population. winter throughout

维普期刊数据库

RAPD analysis of Acanthopanax senticosus genetic diversity

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 1998年第4期 82-85页

作者：戴思兰王丽霞吴乃虎 Beijing 100080 China Chinese Academy of Sciences Institute of Developmental Biology

Random amplified polymorphic DNA (RAPD) analysis has been used widely in detecting genetic diversity at population.level. A total of 49 individual plants of Acanthopanax senticosus from three population. in Northeast China were randomly sampled. Genomic DNA was extracted and purified from fresh leaves. Intensive RAPD analysis was conducted. The proportions of polymorphic RAPD loci in the three population. were 93.5%, 91.3% and 97.6%, respectively. The average values of genetic diversity of A . senticosus within population. were 0.241, 0.363 ana 0.388, The average genetic distances between each population.were 0.435, 0.390 and 0.412. These results revealed a high level of genetic diversity of A . senticosus both within and between its natural population., indicating that it is a flourishing species.

关键词： Acanthopanax senticosus genetic diversity RAPD analysis population.

The True Test of Democracy-The People’s Well-Being

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Today 2022年第1期71卷 48-49页

作者： WILLIAM JONES Chongyang Institute for Financial Studies under Renmin University of China

The proof of whether a particular system is good or bad can only be determined by the impact it has on the welfare of the ***’S State Council Information Office on December 4 released its latest White Paper titled China:Democracy That Works,providing an in-depth picture of the workings of China’s unique consultative and governance system or what is now known as China’s“whole-process people’s democracy.”

关键词： True population. system

Bayes Prediction of Future Observables from Exponentiated population. with Fixed and Random Sample Size

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Statistics 2011年第1期1卷 24-32页

作者： Essam K. AL-Hussaini M. Hussein Department of Mathematics Alexandria University

Bayesian predictive probability density function is obtained when the underlying pop-ulation distribution is exponentiated and subjective prior is used. The corresponding predictive survival function is then obtained and used in constructing 100(1 – ?)% predictive interval, using one- and two- sample schemes when the size of the future sample is fixed and random. In the random case, the size of the future sample is assumed to follow the truncated Poisson distribution with parameter λ. Special attention is paid to the exponentiated Burr type XII population. from which the data are drawn. Two illustrative examples are given, one of which uses simulated data and the other uses data that represent the breaking strength of 64 single carbon fibers of length 10, found in Lawless [40].

关键词： Predictive Density And Survival Functions One- And Two-Sample Schemes Bayes Prediction Exponentiated population. Exponentiated Burr Type XII Distribution Data Of Carbon Fibers

The health of women and children - an integral part of practice of family and community medicine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Family Medicine and Community Health 2018年第3期6卷 95-96页

作者： Li Li Department of Family Medicine and Community Health Case Western Reserve University11000 Cedar AvenueSuite 402ClevelandOH 44106-7136USA

The practice of family and community medicine covers all spectrum of health,including that of women and *** this issue of FMCH,volume 6,issue number 3,four original research articles address various aspects of health in these two subpopulation.,highlighting the comprehensiveness of primary ***,Siuw et al.[1]examined intraocular pressure[IOP]among premenopausal and postmenopausal women in Malaysia and reported a significant impact on IOP by menopause;Ishola et al.[2]developed and validated a new tool to screen postpartum depression among mothers of preterm babies,which demonstrated meritorious validity in the obstetric population.

关键词： population. mother women