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锦州市经济开发区西海工业园区海防堤断面设计 被引量:1
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作者 张春光 于武盛 《农业科技与装备》 2008年第4期73-76,共4页
针对锦州西海工业园区海防堤工程比较特殊的地理位置和实际情况,采用不同方法进行设计。
关键词 人海口 海防堤 断面设计 海潮 洪水 锦州市
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Changing human-environment interactions in medium mountains:the Apuseni Mts(Romania)as a case study 被引量:4
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作者 TELBISZ Tamas IMECS Zoltan +1 位作者 MARl Laszlo BOTTLIK Zsolt 《Journal of Mountain Science》 SCIE CSCD 2016年第9期1675-1687,共13页
The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural ha... The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural hazards. Medium mountains constitute a special case within mountains, because they are more populated but less attractive as tourist destinations than high mountains. In this context, the Apuseni Mts (Romania) are considered as a ease study. In this paper, we apply GIS-based, quantitative methods to characterize the strength and dynamics of human-environment interactions, taking into consideration some environmental factors (elevation, relative height, slope, river distance, lithology, land cover, natural attractions) as well as historical population and recent tourism data. We found that population density has strong (r2〉0.8) relationships with all relief factors (elevation, relative height, slope, river distance), and that best-fit functions are nonlinear. We outlined the varying demographic scenarios by elevation zones and interpreted the historically switching sign of population change versus elevation relationship. We demonstrated that lithology also has an impact on the spatial distribution of population, although it is not independent from the relief effect. The land cover of the mainly cultural landscape is very strongly correlated with relief parameters (especially slope), which suggests good adaptation. We pointed out the dominance of karst objects in the natural tourism potential of the Apuseni Mts and also explored further components of real tourism (spas, heritage, towns). Finally, we concluded that the environmental settings investigated do in fact constrain the spatial framework of society, but soeio-economic changes in history can be explained from the side of society, which conforms to the theory of cultural possibilism. 展开更多
关键词 Human-environment relations ApuseniMountains Geographical information system (GIS) Possibilism TOURISM KARST
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ESTUARINE AND COASTAL CHALLENGES IN CHINA 被引量:20
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作者 陈吉余 陈沈良 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2002年第2期174-181,共8页
Estuaries and coasts are conjunctions of four spheres (atmosphere, lithosphere, hydrosphere and biosphere) and important matter and energy convergence/divergence zones, where developed economy, dense population and hi... Estuaries and coasts are conjunctions of four spheres (atmosphere, lithosphere, hydrosphere and biosphere) and important matter and energy convergence/divergence zones, where developed economy, dense population and highly intensive exploitation induce adverse environmental changes and serious destruction of resources, which have great impacts on coastal sustainable development, especially as the highly intensive development in river basins has direct and pronounced effects on estuaries and their adjacent coasts. In the new century, China’s estuaries and coast are faced with four main challenges: sharp decrease of sediment discharge into the sea, rapid increase of pollution matter into the sea, loss of coastal wetland, and the impacts of global sea level rise on the coastal lowlands of China. Therefore, it is undoubtedly very important and urgent to carry out studies on estuarine and coastal environmental changes, in order to resolve the issue of national sustainable development, especially that of rational use of coastal zone resources. 展开更多
关键词 estuaries and coasts anthropogenic activities environmental changes resource utilization great challenges
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Theoretical and Empidcal Study on Urban Population Carrying Capacity:Case of Haidian District in Beijing 被引量:1
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作者 Zhang Lihua Chert Gang +1 位作者 Xu Xiaoxin Liu Huiwu 《Chinese Journal of Population,Resources and Environment》 北大核心 2008年第2期25-30,共6页
The measurement of urban population carrying capac- ity is the basis for cities' sustainable development.However,the traditional study on population carrying capacity which was based on food supply is not applicab... The measurement of urban population carrying capac- ity is the basis for cities' sustainable development.However,the traditional study on population carrying capacity which was based on food supply is not applicable to the single urban area.This paper built a model for the analysis of urban carrying capacity, and took Haidian District in Beijing as an example to calculate the urban carrying capacity of Haidian District in the future,which was the basis for the improvement of the population carrying capacity.This study would also provide a reference to the meas- urement of the urban population carrying capacity for other cities and districts in China. 展开更多
关键词 population carrying capacity sustainable development case study
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Population parameters and dynamic pool models of commercial fishes in the Beibu Gulf, northern South China Sea 被引量:13
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作者 WANG Xuehui QIU Yongsong +3 位作者 DU Feiyan LIN Zhaojin SUN Dianrong HUANG Shuolin 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第1期105-117,共13页
Length-frequency data of eight commercial fish species in the Beibu Gulf (Golf of Tonkin), northern South China Sea, were collected during 2006-2007. Length-weight relationships and growth and mortality parameters w... Length-frequency data of eight commercial fish species in the Beibu Gulf (Golf of Tonkin), northern South China Sea, were collected during 2006-2007. Length-weight relationships and growth and mortality parameters were analyzed using FiSAT II software. Five species had isometric growth, two species had negative allometric growth, and one species had positive allometric growth. Overall, the exploitation rates of the eight species were lower in 2006 2007 than in 1997-1999: for four species (Saurida tumbil, Saurida undosquamis, Argyrosomus macrocephalus, and Nemipterus virgatus) it was lower in 2006-2007 than in 1997 1999, for two species (Parargyrops edita and Trichiurus haumela) it remained the same, and for the other two species (Trachurus japonicus and Decapterus maruadsi) it was higher in 2006~007 than in 1997-1999. The exploitation rates might have declined because of the decline in fishing intensity caused by high crude oil prices. The optimum exploitation rate, estimated using Beverton-Holt dynamic pool models, indicated that although fishes in the Beibu Gulf could sustain high exploitation rates, the under-size fishes at first capture resulted in low yields. To increase the yield per recruitment, it is more effective to increase the size at first capture than to control fishing effort. 展开更多
关键词 commercial fish population parameters dynamic pool model stock status Beibu Gulf northern South China Sea
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The application of stereo-video technology for the assessment on population change of black rockfish Sebastes schlegeli in a vessel reef area in Haizhou Bay,China 被引量:1
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作者 刘辉 许强 +2 位作者 徐勤增 张迎秋 杨红生 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第1期107-113,共7页
The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DO... The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of >20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P<0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P<0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs. 展开更多
关键词 black rockfish Sebastes schlegeli size composition ABUNDANCE stereo-video vessel reefs
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Current Status of Population Density of Mediterranean Fruit Fly (Ceratitis capitata) in Fruit Orchards in Central Iraq 被引量:1
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作者 M. Z. Khalaf B. H. Hassan A. K. Shbar F. H. Naher A.H Salman N. F. Jabo 《Journal of Agricultural Science and Technology(A)》 2011年第5期773-777,共5页
In the recent years The Mediterranean Fruit fly Ceratitis capitata is distributed in the orchards of central Iraq and caused highly economic losses. This study was conducted in orchards in central Iraq during 2009 and... In the recent years The Mediterranean Fruit fly Ceratitis capitata is distributed in the orchards of central Iraq and caused highly economic losses. This study was conducted in orchards in central Iraq during 2009 and 2010 and made field survey of the insect in four types of orchards (Citrus, Apricot, Figs & Citrus and A mixture of fruit trees) and used for this purpose Tephri Traps supplied with Q-Lure and dimethyl dichloroviny phosphate (DDVP). The present preliminary study has shown that the Mediterranean fruit fly C. capitata has a year round presence in fruit orchards in central Iraq and reached its highest ntunerical density of the pest in citrus orchards during of November and December were 345 and 363 insect/trap per month in citrus orchards and the least numerical density during of January and February while the highest numerical density of the insect in orchards of Apricot in March 2010, Figs & Citrus in August 2009 and a Mixture of fruit trees in November 2009 were 45, 116, 311 insect/trap per month respectively. The population density of the pest was highest is started 2010 compared with 2009, but the high temperature degree (46-51℃) in August 2010 caused decreasing the population density of this pest. C. capitata caused highly economic losses in citrus reached 68% and 71% of the Mandarin and Kaki fruits respectively Currently in Iraq to fight no control method to reduce the economic losses caused by this pest except the use of pesticides GF-120. 展开更多
关键词 Fruit fly (Cerattis capitata) SURVEY Iraq population density fruit orchards.
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Inbreeding and genetic diversity analysis in a hatchery release population and clones of Rhopilema esculentum based on microsatellite markers
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作者 田涛 陈再忠 +2 位作者 王陌桑 胡玉龙 王伟继 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第3期580-586,共7页
Ten microsatellite markers were used to analyze the levels of genetic diversity and inbreeding in a hatchery release population of Rhopilema esculentum Kishinouye (Scypbozoa: Rhizostomatidae). A total of 85 alleles... Ten microsatellite markers were used to analyze the levels of genetic diversity and inbreeding in a hatchery release population of Rhopilema esculentum Kishinouye (Scypbozoa: Rhizostomatidae). A total of 85 alleles were detected in 600 individuals. Within-population levels of observed (Ho) and expected (He) heterozygosity ranged from 0.152 to 0.839 (mean=0.464) and from 0.235 to 0.821 (mean=0.618), respectively. The polymorphism information content (PIC) of each marker ranged from 0.207 to 0.795 with an average of 0.580, indicating that the hatchery population maintained a high level of genetic diversity. Inbreeding levels were estimated in the hatchery population and the inbreeding coefficient was 0.203. This result revealed that a certain level of inbreeding occurred within the population. Meanwhile, we also determined genetic diversity at the clone level. Several polyps from the same scyphistomae were genotyped at the ten microsatellite loci and there was virtually no difference in their genotypes. Furthermore, we calculated the probabilities of exclusion. When both parents were known, the average exclusion probability often loci was 99.99%. Our data suggest that the ten microsatellite markers can not only be used to analyze the identity of individuals but they can also be applied to parentage identification. Our research provides a theoretical basis and technical support for genetic diversity detection and reasonable selection of R. esculentum hatchery populations. These findings support the use of releasing studies and conservation of R. esculentum germplasm resources. 展开更多
关键词 Rhopilema esculentum hatchery release genetic diversity INBREEDING microsatellite markers clones
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Study on Supply and Demand of Intelligent Home-based Aged Care in Shanghai
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作者 Full First PAN Siyu Full Second YAN Yichao LAI Yiyang 《International English Education Research》 2018年第3期38-40,共3页
The 21st century is an era of aging population. With the accelerated aging of the population in our country, and the grim form of population aging, intelligent home-based care has become a concern for the elderly in t... The 21st century is an era of aging population. With the accelerated aging of the population in our country, and the grim form of population aging, intelligent home-based care has become a concern for the elderly in the area of ??care. This paper starts from the new concept of intelligent home-based care services and defines intelligent home care services. It also summarizes the current theoretical researches related to domestic research, which is of great significance for the investigation and research conducted in the later stage of research. 展开更多
关键词 home care INTELLIGENCE supply and demand service content
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Analysis of the necessity of Shanghai's long-term care insurance
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作者 Yang Jie 《International English Education Research》 2015年第6期68-69,共2页
The aging population of Shanghai is China one of the most serious city, is also one of the cities of the aging problem is prominent. As a result, the city's endowment pressure also with aging and aging aggravate grad... The aging population of Shanghai is China one of the most serious city, is also one of the cities of the aging problem is prominent. As a result, the city's endowment pressure also with aging and aging aggravate gradually increased, especially the old man nursing problems become the main problem in society. Study abroad to establish a long term care insurance comprehensive factors, considering the feasibility of the long-term care insurance in Shanghai, alleviate the pressure of the pension, the construction of a harmonious society. 展开更多
关键词 The necessity Long-term care insurance.
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Restoration of sea eagle population:A review 被引量:1
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作者 Josef RAJCHARD Jan PROCHZKA 《Current Zoology》 SCIE CAS CSCD 北大核心 2009年第5期315-318,共4页
The population density of the white-tailed sea eagle Haliaeetus albicilla is very low in many countries. In last twenty years, the sea eagle population in South Bohemia was restored by strict protection subsidized by ... The population density of the white-tailed sea eagle Haliaeetus albicilla is very low in many countries. In last twenty years, the sea eagle population in South Bohemia was restored by strict protection subsidized by reintroduction, The active help consisted of feeding during winter and building of artificial nests. A new sea eagle breeding population arose in the Treboǎ basin area in the early 1980' s. Until this time sea eagles had used former breeding places only for wintering, probably coming from the Baltic. The South Bohemian sea eagle population is very unique: it exists in a densely man-occupied landscape, mainly in areas with very intensive carp breeding in artificial fishponds and was partly artficially (help to wintering birds and reintroduction of some individuals) restored. The experience from South Bohemia may have importance for populations of the sea eagle in other areas of its occurence, primarily in the continental conditions [ Current Zoology 55 (5) : 315 - 318, 2009]. 展开更多
关键词 Sea eagle Haliaeetus albicilla
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Study on The Basic Public Health Service in Shanghai
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作者 ZHAO Qing 《International English Education Research》 2016年第12期96-98,共3页
It is increasingly found that medical investment is not the only effective means to improve the national health level. The basic public health service, which is dominated by disease control and prevention, is paid mor... It is increasingly found that medical investment is not the only effective means to improve the national health level. The basic public health service, which is dominated by disease control and prevention, is paid more and more attention.This paper analyzes the relationship between the migrant population and the population of the city's household registration to the basic public health service. Access to basic public health services and satisfaction of the system, analysis of the factors affecting the satisfaction of the basic public health services in Shanghai revealed the problems and causes of development. Finally, putting forward the concrete countermeasures and suggestions for perfecting and improving the basic public health service in Shanghai. 展开更多
关键词 basic public health service SATISFACTION countermeasure and suggestion
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Biological Status of Indus River Dolphin (Platanista Minor Owen) in Indus River, Northern Pakistan
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作者 Farzana Perveen Sardar Azher Mehmood Shabbir Ahmed Zia Ur Reman 《Journal of Life Sciences》 2011年第1期39-47,共9页
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... 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. 展开更多
关键词 DOLPHIN endangered or critically endangered Indus river Northern Pakistan protection population.
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Population Structure and Sexual Maturity of the Pufferfish Lagocephalus sceleratus (Osteichthyes, Tetraodontidae) in the Lebanese and Syrian Marine Waters (Eastern Mediterranean)
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作者 Gaby Khalaf Adib Saad +3 位作者 Sherif Jemaa Waad Sabour Myriam Lteif Stefano Lelli 《Journal of Earth Science and Engineering》 2014年第4期236-244,共9页
The pufferfish Lagocephalus sceleratus is an invasive Lessepsian species of Indo-Pacific origin that has established an increasing population over the past decade in the Levantine basin of the Mediterranean. Besides i... The pufferfish Lagocephalus sceleratus is an invasive Lessepsian species of Indo-Pacific origin that has established an increasing population over the past decade in the Levantine basin of the Mediterranean. Besides its toxicity due to the accumulation of tetrodotoxin in its body, it is causing damage to fishing gears and fishermen's catches. This study aims to provide data on the population structure and sexual maturity of this species in the eastern basin of the Mediterranean. A total of 214 individuals were collected in the coastal marine waters of Lebanon and Syria, between January 2012 and June 2013 by means of different types of nets and lines, on soft bottoms, at depths ranging from 10 m to 170 m. The TL (total length) of the samples varies between 10.8 cm and 71 cm. The most common size classes, represented by 125 individuals, are the ones between 30 cm and 50 cm TL, with a bulge at 40 cm, represented by 44 individuals. The average TL is 43.99 cm (standard deviation: SD = 17.65) for both males and females. The TW (total weight) of the specimens ranges between 14 g and 4,603 g with an average value of 1,458.52 g (SD = 1,329.49). The sex ratio (M/F) is 1:1.35 with a total number of 87 males, 118 females and nine unidentified individuals. The weight-length relationship (TW = aTLb) shows a negative allometric growth with b = 2.9481 and R2 = 0.9806. The condition factor (K) is close to one for all samples. The average value of the GSI (gonadosomatic index) shows a substantial increase from winter to spring. The spawning takes place between April and June. 展开更多
关键词 Lagocephalus sceleratus Lessepsian species population structure eastern Mediterranean.
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Perfect Shanghai Community Support Mechanism importance
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作者 CHEN jian 《International English Education Research》 2016年第5期4-6,共3页
With the aging of our population is growing significantly, pension issues are also increasingly prominent in the family pension, social pension and retirement communities, and retirement communities have both advantag... With the aging of our population is growing significantly, pension issues are also increasingly prominent in the family pension, social pension and retirement communities, and retirement communities have both advantages and both have their own characteristics and become an effective means to solve the pension problem, Shanghai is currently analyzing the situation and problems of the pension on the basis of the Shanghai community care services continue to improve mechanisms to forward the healthy and orderly development of Shanghai pension service mechanism. 展开更多
关键词 GOVERNMENT procurement community CARE prevention MECHANISM
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From the empty nest elderly to explore the era of Internet + in Shanghai community enctowment problems at home
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作者 Wang Hainan 《International English Education Research》 2015年第6期92-94,共3页
At present, China's population aging of unprecedented increase, empty older family question discussion and solve the problem of pension, is the urgent needs of the population aging in our country. Compared with the t... At present, China's population aging of unprecedented increase, empty older family question discussion and solve the problem of pension, is the urgent needs of the population aging in our country. Compared with the traditional family endowment, institution endowment and community endowment that occupy the home can guarantee the old man in his own enjoy the professional care services in the community, its unique advantage by relevant government departments, institutions and community in favor of people. At the same time, the rapid development of science and technology will we're in a new era of big data, set offa wave of intelligent city, the era of Internet + city community home endowment also ushered in the new opportunities and challenges, "community O2O" pension mode is more and more clear, the Internet information technology will be in the development of urban community endowment that occupy the home is very imoortant. 展开更多
关键词 empty older family endowment "community O2O Internet
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Study of the Population Carrying Capacity of Water and Land in Hainan Province 被引量:2
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作者 HAO Qing FENG Zhiming +3 位作者 YANG Yanzhao YOU Zhen CHENG Ping DENG Ling 《Journal of Resources and Ecology》 CSCD 2019年第4期353-361,共9页
In recent years, the rapid growth of population in Haikou and Sanya has caused extensive concern about the carrying capacity of Hainan Province. To formulate scientific population and environmental policies, it is nec... In recent years, the rapid growth of population in Haikou and Sanya has caused extensive concern about the carrying capacity of Hainan Province. To formulate scientific population and environmental policies, it is necessary to research the relationship between population, carrying capacity and economic growth. In this paper, three indicators, grain production, nutrient composition of agricultural products and water resources, are used to measure carrying capacity quantitatively;the employment elasticity coefficient method is used to set the employment elasticity coefficient and the growth rate of regional GDP to estimate the total population needed to support economic growth;PADIS-INT population forecasting software that has parameters to track total fertility rate and net migration rate is used to predict demographic changes. The results show that, as of 2050, the total population of Hainan Province will not have exceeded the upper limit of the carrying capacity of land and water resources. In general, there is no overpopulation problem in the province, but there may be structural problems related to population, such as a large proportion of elderly people, labor shortages, and a high social dependency ratio. It is suggested that the local government should adopt positive population policies, improve the management of natural resources and the environment, and guide the balanced development of population in the province. 展开更多
关键词 carrying capacity economic growth POPULATION HAINAN
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Ecological variation along the salinity gradient in the Baltic Sea Area and its consequences for reproduction in the common goby 被引量:1
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作者 Isabel MUCK Katja U. HEUBEL 《Current Zoology》 SCIE CAS CSCD 2018年第2期259-270,共12页
Although it has become clear that sexual selection may shape mating systems and drive speciation, the potential constraints of environmental factors on processes and outcomes of sexual selection are largely unexplored... Although it has become clear that sexual selection may shape mating systems and drive speciation, the potential constraints of environmental factors on processes and outcomes of sexual selection are largely unexplored. Here, we investigate the geographic variation of such environmental factors, more precisely the quality and quantity of nest resources (bivalve shells) along a salinity gradient in the Baltic Sea Area (Baltic Sea, Sounds and Belts, and Kattegat). We further test whether we find any salinity-associated morphological differences in body size between populations of common gobies Pomatoschistus microps, a small marine fish with a resource-based mat- ing system. In a geographically expansive field study, we sampled 5 populations of P. microps occurring along the salinity gradient (decreasing from West to East) in the Baltic Sea Area over 3 consecutive years. Nest resource quantity and quality decreased from West to East, and a correla- tion between mussel size and male body size was detected. Population density, sex ratios, mating- and reproductive success as well as brood characteristics also differed between populations but with a less clear relation to salinity. With this field study we shed light on geographic variation of distinct environmental parameters possibly acting on population differentiation. We provide insights on relevant ecological variation, and draw attention to its importance in the framework of context-dependent plasticity of sexual selection. 展开更多
关键词 aquatic ecology body size environmental gradient nest availability nesting resources sexual selection.
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C and N stable isotope analysis of human and animal bones at the Beiqian site 被引量:2
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作者 WANG Fen SONG YanBo +3 位作者 LI BaoShuo FAN Rong JIN GuiYun YUAN ShiLing 《Science China Earth Sciences》 SCIE EI CAS 2014年第3期408-414,共7页
The Beiqian site,located in Jimo city,Qingdao,went through three archaeological excavations,and a large number of human and animal bones in the Dawenkou culture and the Zhou Dynasty period were unearthed.By carbon and... The Beiqian site,located in Jimo city,Qingdao,went through three archaeological excavations,and a large number of human and animal bones in the Dawenkou culture and the Zhou Dynasty period were unearthed.By carbon and nitrogen stable isotope analysis,the diet of ancestors is expected to be recovered,and the domesticated plants and animals will be discussed.The investigated results showed that the food structure of ancestors in both periods included food crops,mainly C4 foods,and meat,mainly marine shellfish and livestock.For domestic pigs,they mainly eat C3 plants,and were affected by the lifestyle of ancestors.This study also showed that the diet of ancestors is the shellfish rather than marine fish despite the Beiqian site is located near the shoreline.We can conclude that the diet of ancestors in Dawenkou culture period included millet crops(C4plants),shellfish,marine food,and livestock,representing the lifestyle of farming,domestication,and fishing,supplemented by hunting.In the Zhou dynasty period the meat resource was enriched by domesticated animals and marine fisheries,and the living conditions were significantly improved. 展开更多
关键词 neolithic age Dawenkou culture Zhou Dynasty stable isotope analysis DIET
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Current hypotheses to explain genetic chaos under the sea 被引量:2
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作者 Bjarki ELDON Florentine RIQUET +2 位作者 Jon YEARSLEY Didier JOLLIVET Thomas BROQUET 《Current Zoology》 SCIE CAS CSCD 2016年第6期551-566,共16页
Chaotic genetic patchiness (CGP) refers to surprising patterns of spatial and temporal genetic structure observed in some marine species at a scale where genetic variation should be efficiently homogenized by gene f... Chaotic genetic patchiness (CGP) refers to surprising patterns of spatial and temporal genetic structure observed in some marine species at a scale where genetic variation should be efficiently homogenized by gene flow via larval dispersal. Here we review and discuss 4 mechanisms that could generate such unexpected patterns: selection, sweepstakes reproductive success, collective dispersal, and temporal shifts in local population dynamics. First, we review examples where genetic differentiation at specific loci was driven by diversifying selection, which was historically the first process invoked to explain CGP. Second, we turn to neutral demographic processes that may drive genome-wide effects, and whose effects on CGP may be enhanced when they act together. We discuss how sweepstakes reproductive success accelerates genetic drift and can thus generate genetic structure, provided that gene flow is not too strong. Collective dispersal is another mechanism whereby genetic structure can be maintained regardless of dispersal intensity, because it may prevent larval cohorts from becoming entirely mixed. Theoretical analyses of both the sweepstakes and the collective dispersal ideas are presented. Finally, we discuss an idea that has received less attention than the other ones just mentioned, namely temporal shifts in local population dynamics. 展开更多
关键词 asynchronous population dynamics chaotic genetic patchiness collective dispersal kin aggregation larval dispersal multiple-merger coalescent sweepstakes reproductive success.
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