The Influences of Population Age Structure＇s Changes on the Export Commodity Structure

For a long time, China has large population, so the labor-intensive products become the comparative advantage.This paper analyzes the influences of population age structure＇s changes on the export commodity structure of our country and draws conclusions.

Population Shrinkage in Resource-dependent Cities in China: Processes, Patterns and Drivers

Resource-dependent cities(RCs)are a vulnerable group of urban settlements that often face population shrinkage;however,population changes in RCs in China are not well understood.This study offers new insight into this matter through a robust analysis that features a longer time scale,a larger sample of RCs,and a finer unit of analysis.It finds new evidence that problems of population shrinkage in RCs are more serious than previous literature has suggested.Approximately 30%of the studied units have experienced either long-term or short-term population shrinkage,and many more are experiencing a slowing down of population growth.Problems are especially common among three types of RCs:the resource-depleted RCs,the forestry-based RCs,and RCs in Northeast China.These results underscore transition policy inadequacies in addressing population loss,and call for a more comprehensive and diversified population policy that tackles the multifaceted factors that contribute to population shrinkage,including lack of industrial support,maladjustment to market oriented reformation,poor urban environment and natural population decline.

Population Change of OH and H2O in Water Vapor Glow Discharge Measured Using Concentration Modulation Spectroscopy

A distributed feedback laser with a wavelength of 2.8μm was used to measure the species produced by water vapor glow discharge.Only the absorption spectra of OH radicals and transient H2O molecules were observed using concentration modulation(CM)spectroscopy.The intensities and orientations of the absorption peaks change with the demodulation phase,but the direction of one absorption peak of H2O is always opposite to the other peaks.The different spectral orientations of OH and H2O reflect the increase or the decrease of the number of particles in the energy levels.If more transient species can be detected in the discharge process,the dynamics of excitation,ionization,and decomposition of H2O can be better studied.This study shows that the demodulation phase relationship of CM spectrum can be used to study the population change of molecular energy levels.

Regional Differentiation Regularity and Influencing Factors of Population Change in the Qinghai-Tibet Plateau, China

The Qinghai-Tibet Plateau(QTP) is the most unique region of human-land relations, and its main factor is population. By building a population and space dataset of the QTP at the township level from 1982 to 2017, this paper presents the pattern evolvement and regional distribution characteristics of township-level population in the QTP in detail for the first time. By using Geodetector method to analyze the influencing factors of township-level population change in the QTP, this paper provides scientific foundations for studying the Third Pole, ecological environment protection of the QTP, and human-land relations. The conclusions are as follows:1) The population spatial distribution is not balanced at the township level, presents the regional differentiation characteristics of ‘dense in southeast and sparse in northwest’ along the ‘Qilian-Jilong Line’, and demonstrates the phenomenon of population center of gravity moving to the hinterland of the plateau at an accelerated speed;2) The township-level population develops in a decentralized trend in general, and the cold-and hot-spot distribution of population has prominent spatial distribution characteristics. The population hot spots are concentrated in the surrounding areas of Xining, Golmud, Hotan and Lijiang;3) The population of the QTP is increasing, and the inter-annual change of township population has a relatively stable regional regularity;4) The level of per capita income is the leading factor in the change of township population, and its effect intensity is increasing continuously. The relative effect intensity of urbanization level and location conditions on population change has decreased significantly after 2000. The adaptability of living environment,such as topography and climate, has little influence on population change.

Responses of Housing Price under Different Directions of Population Change:Evidence from China's Rust Belt

Population growth has been widely regarded as an important driver of surging housing prices of urban China,while it is unclear as yet whether population shrinkage has an impact on housing prices that is symmetrical with that of population growth.This study,taking 35 sample cites in Northeast China,the typical rust belt with intensifying population shrinkage,as examples,provides an empirical assessment of the roles of population growth and shrinkage in changing housing prices by analyzing panel data,as well as a variety of other factors in related to housing price,during the period of 1999–2018.Findings indicate that although gap in housing prices was widening between population growing cities and population shrinking cities,the past two decades witnessed an obvious rise in housing prices of those sample cities to varying degree.Changes in population size did not have a statistically significant impact on housing prices volatility of sample cities,because population reduction did not lead to a decline in housing demand correspondingly and an increasing housing demand aroused by population growth was usually followed by a quicker and larger housing supply.The rising housing prices in sample cities was mainly driven by factors like changes in land cost,investment in real estate,GDP per capita and household number.However,this does not mean that the impact of population shrinkage on housing prices could be ignored.As population shrinkage intensifies,avoiding the rapid decline of house prices should be the focus of real estate regulation in some population shrinking cities of Northeast China.Our findings contribute a new form of asymmetric responses of housing price to population growth and shrinkage,and offer policy implications for real estate regulation of population shrinking cities in China’s rust belt.

Investigation of the Population Change of Cinnamomum camphora(L.) Presl. during the Past Century in Wuxi

Through investigating the population change of Cinnamomum camphora(L.) Presl. in Wuxi City, the research found that C. camphora(L.) Presl. in the past century had already become common species from rare species, then explored the causes, advantages and disadvantages of the change. In view of sustainable development of urban greening, zonal vegetation and fl ora, this paper explored the scientifi c and reasonable application of tree species and also protection of urban plant diversity.

Impact Analysis of Bridging on Remote Island Population

We analyzed the determinants of building bridges after comparing bridge islands and non-bridge islands.In addition,we examined the population change before and after the bridge building and the factors influencing the change.As a result,a remote island with high cost-effectiveness was selected and bridged.The early bridge was built in remote islands with fragile social infrastructure,and the outflow of population was suppressed owing to the improvement in standard of living by securing the medical care and education available in the bridge destination.However,around the year 2000,there are few remote islands where the changes in populations are influenced after a bridge was built.

Research on the Influence of Population Structure on Economic Growth: Based on the Provincial Panel Data Model

In recent years, the international environment and conditions of China’s economic development have undergone profound and complex changes, but in the middle and long term, China’s economy has been maintaining a stable medium-high speed development. It is remarkable that population changes bring about changes in economic development;especially the aging of the population has a particularly significant impact on economic growth. Therefore, based on the inter-provincial panel data of 31 provinces and municipalities from 2011 to 2019, this paper mainly studies the impact of population change on economic growth by establishing a solid fixed effect model. The results show that there is a long-term equilibrium relationship between population structure and economic growth, and population structure has a significant positive impact on economic development. In addition, there are regional differences in the positive and significant relationship between the two.

Wildlife Population Change in Africa from the Eyes of the Public—The Case of Mara Enoonkishu Conservancy in Southern Kenya

The aims of the study were to: 1) determine the wildlife population trends in the Mara Enoonkishu Conservancy from the eyes and minds of the public, 2) assess the recent trends in wildlife populations based on actual scientific counts, and 3) compare the two patterns and establish whether they are similar or not. The solicitation of public views was based on household surveys using a standard questionnaire which was administered to 115 randomly selected respondents. The dominant wildlife species according to 39% of the respondents was the elephant followed by the zebra with 35%. 40% of the respondents indicated that the rhino population had declined followed by wild dogs (7%) and cheetah (6%). The actual counts showed that the herbivores with increasing populations included the rhino (r2 = 0.9992), impala (r2 = 0.9824), Thomson’s gazelle (r2 = 0.6965), Grant’s gazelle (r2 = 0.7052), elephant (r2 = 0.5798), and topi (r2 = 0.4426) while the increasing predators included the lion (r2 = 1.000), cheetah (r2 = 0.9093) and hyena (r2 = 0.8462). The actual wildlife counts appeared to tally with the public views only for the elephant and zebra. The actual counts contradicted the public views in terms of the rhino, lion and gazelles whose numbers were on the increase but the people did not appear to notice. Based on this, it was concluded that the public view on the wildlife population trend was not similar to the actual wildlife population status on the ground based on scientific monitoring.

Changes in the size of China’s population over 70 years

Based on the data from China Statistical Yearbooks and China’s population cen-suses,this paper provides a systematic introduction to changes in the size of China’s population over the 70 years since the founding of the People’s Republic of China(PRC)in 1949.It analyzes population size and crude birth rate,crude death rate,natural increase rate and total fertility rate,all of which have an impact on popula-tion size in both the temporal and spatial dimensions.The paper divides China into sluggish Average Annual Growth Rate(AAGR)regions,recovering AAGR regions,and thriving AAGR regions.Challenges that may result from China’s demographic changes and strategies to address those challenges are discussed.

Population Change and Resulting Slowdown in Potential GDP Growth in China

As a result of the shrinking working age population （aged 15 to 59 years）, all factors that have driven China＇s rapid economic growth over the past 30years tend to diminish from 2010. The present paper estimates the average annual growth rate of potential output to be 7.2percent over the 12th Five-year Plan period and 6.1 percent over the 13th Five-year Plan period. Future sustainable growth requires furthering economic reform in related areas to enhance potential growth. This paper simulates two scenarios in which both an increase in labor force participation and improvement in total factor productivity can significantly enhance the potential GDP growth rate. Relevant policy implications are discussed.

Construction of a refined population analysis unit based on urban forms and population aggregation patterns

The population analysis unit(PAU)is the basic unit employed in studies of urban populations.The commonly used PAUs are mostly administrative divisions,regular geographic grids.However,these units are different from urban forms,and cannot be used to consider the characteristics of population distributions and flow changes.In this study,we proposed a method for constructing a fine population analysis zone(FPAZ)based on the population aggregation pattern and urban form elements.First,considering the spatial structure of a city and the fine-grained demands of population analysis,the basic analysis unit was divided according to the functional heterogeneity of the population activity region at the micro-scale by combining urban form elements.Next,a population aggregation preference model was established by considering the spatial distribution characteristics of the local aggregation of the urban population flow and long-term stability characteristics depending on the dynamic changes in entrances and exits.Finally,we divided the FPAZ combined with the microstructural elements.Experimental results showed that compared with other types of PAUs,the FPAZ was more consistent with the urban morphology and was an appropriate and general spatial unit for expressing the accurate characteristics of population distributions and changes at the micro-scale.

The relationships between land use change and demographic dynamics in western Jilin province

Demographic change was thought to although there were several interacting factors be the most major driver of land use change involved, especially in the developing coun- tries. In this paper, we selected western Jilin province in China as the study area to provide a case study for understanding the relationship between spatial-temporal pattern of the land use change and population dynamics from 1975 to 2010. The results showed that the change of farmland area percentage could be modeled well by using a quadratic function, the least area percentage of farmland was 15.4% in areas where the population density was 0 peo- ple/km2, and farmland area percentage had a greatest value of 94.8% when population den- sity was 199.25 people/km2. The area percentage of grassland, water body and wetland de- creased exponentially with population density increased. The relationship between land use degree and population density could be modeled well by using a logistic regression models. Due to economic growth and technological progress and the existence of Hollow Village phenomenon, land use degree still increased in areas where population density was negative growth. In addition, land use dynamics increased exponentially with population density change. Land use relative change of woodland, grassland, built-up land and wetland were proportional to population density change. According to the simulation results of the land use structure and land use degree, Da＇an and Zhenlai had the greatest possibility to be further reclaimed. As sensitive and fragile areas, it was of significance to study environmental pro- tection and ecologic construction on Tongyu and Qian＇an.