Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics, astronautics and civil aviation.

Which Neighborhoods Have Easier Access to Online Home Delivery Services?A Spatiotemporal Accessibility Analysis in Nanjing,China

The rise in online home delivery services(OHDS)has had a significant impact on how urban services are supplied and used in recent years.Studies on the spatial accessibility of OHDS are emerging,but few is known about the temporal dimension of OHDS accessibility as well as the geographic and socioeconomic differences in the spatiotemporal accessibility of OHDS.This study measures the spatiotemporal accessibility of four types of OHDS,namely leisure,fresh and convenient,medical,and catering services.The geographic and socioeconomic disparities in the spatiotemporal accessibility of these four types of OHDS are then identified using spatial statistical methods and the Kruskal-Wallis test(K-W test).The case study in Nanjing,China,suggests that:1)spatiotemporal accessibility better reflects the temporal variation of OHDS accessibility and avoids overestimation of OHDS accessibility when only considering its spatial dimension.2)The spatiotemporal accessibility of OHDS varies geographically and socioeconomically.Neighborhoods located in the main city or neighborhoods with higher housing prices,higher population density,and higher point of interest(POI)mix have better OHDS spatiotemporal accessibility.Our study contributes to the understanding of OHDS accessibility from a spatiotemporal perspective,and the empirical insights can assist policymakers in creating intervention plans that take into account variations in OHDS spatiotemporal accessibility.

IEC Promotion Center (Nanjing) signs an agreement with State Grid Fujian Electric Power

The IEC Promotion Center(Nanjing)signed a development cooperation agreement with State Grid Fujian Electric Power Co.,Ltd.on April 23 in Nanjing city,Jiangsu province.The signing ceremony was witnessed by Shu Yinbiao,the 36th President of IEC,Academician of Chinese Academy of Engineering,and President of Chinese Society for Electrical Engineering,Ruan Qiantu,Chair of the Board and Party Secretary of State Grid Fujian Electric Power Co.,Ltd.,Shan Shewu,Chair of the Board and Party Secretary of NARI Group,as well as Fan Xiangqian and Yu Qing,Director and Deputy Director of Management Committee of Nanjing Chilin Technology Innovation Park.

Bird Resources and Avifauna of Zijin Mountain in Nanjing

The survey of bird species in Zijin Mountain area of Nanjing were conducted from September 2005 to April 2007.A total of 164 species belonging to 15 orders and 44 families were recorded,including 59 resident birds,34 summer migrants,41 winter migrants,29 passing birds,and one vagrant bird.There were 25 species listed as key protected wild animal species in China,and 56 species in key protected birds in Jiangsu Province.The avifauna was composed of Palaearctic realm species(51.22%),Oriental realm species(40.24%)and cosmopolitan species(8.54%),showing the characteristics of north-south transition.In summary,there are abundant bird species in Zijin Mountain,but with low population number and density.

TONIGHT,WE ARE YOUNG--‘New Youth,New Future’Asian Youth Music Festival rocks Nanjing

The“New Youth,New Future”Asian Youth Music Festival kicked off in Nanjing,capital of east China’s Jiangsu Province,on October 28.Talented young artists,bands,and singers from China,Japan,the ROK,and ASEAN countries gathered to share a stage and be part of a youth musical and cultural feast dedicated to peace and friendship.The festival attracted more than 20,000 spectators.

Influence of artificial freezing onliquefaction characteristics of Nanjing sand

Purpose–This study purposes to study the influence of artificial freezing on the liquefaction characteristics of Nanjing sand,as well as its mechanism.Design/methodology/approach–was studied through dynamic triaxial tests by means of the GDS dynamic triaxial system on Nanjing sand extensively discovered in the middle and lower reaches of the Yangtze River under seismic load and metro train vibration load,respectively,and potential hazards of the two loads to the freezing construction of Nanjing sand were also identified in the tests.Findings–The results show that under both seismic load and metro train vibration load,freeze-thaw cycles will significantly reduce the stiffness and liquefaction resistance of Nanjing sand,especially in the first freezethaw cycle;the more freeze-thaw cycles,the worse structural behaviors of silty-fine sand,and the easier to liquefy;freeze-thaw cycles will increase the sensitivity of Nanjing sand’s dynamic pore pressure to dynamic load response;the lower the freezing temperature and the effective confining pressure,the worse the liquefaction resistance of Nanjing sand after freeze-thaw cycles;compared to the metro train vibration load,the seismic load in Nanjing is potentially less dangerous to freezing construction of Nanjing sand.Originality/value–The research results are helpful to the construction of the artificial ground freezing of the subway crossing passage in the lower reaches of the Yangtze River and to ensure the construction safety of the subway tunnel and its crossing passage.

Study on Flora Components and Floristic Characteristic of Urban Forest in Nanjing

Based on the thorough investigation of the components of urban forest in Nanjing and the collection of samples,it is concluded that there are 1 500 species(including subspecies) of vascular plants belonging to 572 genera of 172 families,among which there are 63 species of ferns belonging to 36 genera of 25 families,1 437 species of seed plants belonging to 536 genera of 147 families.The characteristics are that the flora is rich in species,complex in geographic composition,and possess the distinct transferring quality from tropical to temperate zone.Besides,it is characterized with certain ancient nature,and the peculiar elements are comparatively simple.

Enlightenment of Smart Growth Theories on the Development of Nanjing City,China

The background and connotations of smart growth theories of America were introduced first,spatial expansion features of Nanjing City were summarized as the following 3 points:population growth,expansion of urban spaces and industrial expansion.And then problems emerged in the spatial expansion were pointed out as:A."Sprawl" in the urban development;B.Improper internal spatial structure of the city;C.Destructed historical and cultural context of the city.Smart growth theories were applied in this study to analyze potential problems in the spatial expansion of Nanjing,corresponding countermeasures were given as:defining proper growth boundaries,restricting total growth volume,saving land;strictly controlling growth intensity,fully utilizing resources,intensively using land;scientifically evaluating growth benefits,promoting recycling of resources,and realizing sustainable growth.By learning from overseas smart growth theories,the authors hoped to provide useful references for the overall land use planning and urban planning of Nanjing City.

Effects of Different Sowing Dates and Sites on Grain Quality and RVA Profile of Nanjing 46,a Popular Cultivar of Japonica Rice(Oryza sativa L.)

[Objective] This study was performed to determine the effects of sowing dates and sites on grain quality and Rapid Viscosity Analyzer （RVA） profile of Nan-jing 46. [Method] The field experiments were carried out at five sites in Jiangsu Province, and in every site, the seeds were sowing on seven different dates. RVA related indices were measured after harvest. [Result] Along with the delay of sowing date, the mil ing quality of Nanjing 46 increased at first and then reduced, while its appearance quality went up and the cooling and edible quality decreased. With the sowing sites moving southward, the rice mil ing quality, appearance quality, and cooling and edible quality of Nanjing 46 decreased at first and then increased. Grain traits responded variably to the sowing dates and sites. The brown rice rate, grain width, grain length, length/width, mil ed rice rate and head mil ed rice rate were less affected, while the chalky rice rate and chalkiness degree were more af-fected. The gelatinization temperature, protein content, amylose content, gel consis-tency and eating value were in-between. The RVA profile analysis revealed that the breakdown value, setback value and pasting temperature were affected by the sow-ing date and geographical environment. The peak viscosity, hot viscosity, cool vis-cosity and peak time were influenced more by geographical environment. With the delay of the sowing date, peak viscosity, hot viscosity, cool viscosity, setback value and pasting temperature decreased at first and then increased, while the breakdown value changed inversely, and the peak time did not exhibit a regular trend. With the decrease of latitude, the peak viscosity, hot viscosity, breakdown and cool viscosity declined at first and then increased, the setback value and peak time decreased, while the pasting temperature increased. [Conclusion] This study wil provide refer-ences for the effective production of Nanjing 46.

Analysis of the Tourism Image of Urban Waterfront Nanjing City

The quantitative analysis method was used to measure the tourism image of Nanjing waterfront to make clear its composition.An evaluation method was also adopted in terms of cognitive image,affective image and the whole image,which may offer some references for the evaluation of other tourism images in urban waterfront of the same kind.

Study on Plant Community Feature of Nanjing Temple Gardens

10 temple courtyards and 10 temple gardens were chosen as the research object in Nanjing.There were 146 species of vascular plants(including variety),which belong to 96 genera and 63 families.The Richness index,Simpson index,Species diversity and Similarity index of the plant community were analyzed.The results showed:①The dominant species of temple courtyards and temple gardens were all trees;the density of shrub layer(0.32 strains/m2) was greater than that of the tree layer(0.21 strains/m2).And the density of tree layer(2.4 strains/m2) and shrub layer(4.5 strains/m2) in temple gardens were totally higher than those of temple courtyards.②Both the Simpson index and the Species diversity in temple garden plots were higher than those of the temple courtyard plots;The Pielou index was at a higher level both in tree layer and shrub layer,which indicated that quantities of each tree species were on an average level.③The Similarity index in temple gardens was higher than that of the temple courtyards,both less than 50%,which indicated that the repetition rate of each tree species was obviously greater in temple gardens than in temple courtyards.

Study on the Urbanization of Nanjing City and Its Greenhouse Effect

To study the relationship between the enlargement of Nanjing City and urban greenhouse effect,the temperature of Nanjing Station and its suburban stations during 1961-2000 was analyzed.The results showed that the temperature of Nanjing area has increased gradually and the urban heat island effect has developed quickly.The average temperature increment in winter is the greatest,followed by that in spring,autumn and summer,most of which was caused by the greenhouse effect in Nanjing area.Finally several effective countermeasures have been proposed correspondingly.

Survey and Countermeasures on the Public Facilities in Urban Parks——with Urban Parks in Nanjing City as Study Cases

Urban park is an important outdoor leisure space for urban citizens. The public facility in urban park is a functional environmental element connecting human beings and environment. Through analyzing the present situation and application of public facilities in urban parks of Nanjing City, the existing problems and countermeasures were pointed out, in order to provide theoretical references for the construction of public facility in the urban parks.

Investigation on the Characteristics of the Senior Citizens' Activities in the Parks and Greenbelts——A Case Study of Nanjing City

From the perspective of senior citizens,questionnaire survey and field investigation were carried on and analyzed in three parks in Nanjing City.The results showed that outdoor activities are the principal ways for the senior citizens to spend their time,the parks near home is their prior choice,and the radiation range of the park and greenbelt mostly is no more than 2 km;most of the senior citizens come to parks on foot and the parks are always within 30 minutes walking distance;the senior citizens always have fixed partners and groups for their exercise-dominant activities.

Agricultural Development of Nanjing Suburban Counties based on Contribution Models of Production Factors

According to data in Nanjing Statistical Yearbook, contribution made by agricultural production factors was analyzed with contribution models of agricultural factors and the results showed that with restriction of labor force and land, Nanjing suburban counties have entered into a stage of ＂high input-high output＂, considering no matter from agricultural total value of output or from agricultural added value. In future, structure configuration of agricultural input factors should be optimized in Nanjing suburban counties by technology input to improve agricultural technology and technical efficiency in order to further achieve sustainable development of agriculture.

Influence of Atmospheric Particulate Matter on Ozone in Nanjing,China:Observational Study and Mechanistic Analysis

Particulate matter with diameters of 2.5 μm or smaller(PM_(2.5)) and ozone(O_3) are major pollutants in the urban atmosphere. PM_(2.5) can affect O_3 by altering the photolysis rate and heterogeneous reactions. However, these two processes and their relative importance remain uncertain. In this paper, with Nanjing in China as the target city, we investigate the characteristics and mechanism of interactions between particles and O_3 based on ground observations and numerical modeling.In 2008, the average concentrations of PM_(2.5) and O_3 at Caochangmen station are 64.6 ± 47.4 μg m^(-3) and 24.6 ± 22.8 ppb,respectively, while at Pukou station they are 94.1 ± 63.4 μg m^(-3) and 16.9 ± 14.9 ppb. The correlation coefficient between PM_(2.5) and O_3 is -0.46. In order to understand the reaction between PM_(2.5) and O_3, we construct a box model, in which an aerosol optical property model, ultraviolet radiation model, gas phase chemistry model, and heterogeneous chemistry model,are coupled. The model is employed to investigate the relative contribution of the aforementioned two processes, which vary under different particle concentrations, scattering capability and VOCs/NOxratios(VOCs: volatile organic compounds;NOx: nitric oxide and nitrogen dioxide). Generally, photolysis rate effect can cause a greater O_3 reduction when the particle concentrations are higher, while heterogeneous reactions dominate O_3 reduction with low-level particle concentrations.Moreover, in typical VOC-sensitive regions, O_3 can even be increased by heterogeneous reactions. In Nanjing, both processes lead to O_3 reduction, and photolysis rate effect is dominant. Our study underscores the importance of photolysis rate effect and heterogeneous reactions for O_3, and such interaction processes should be fully considered in future atmospheric chemistry modeling.

On the Evolution and Structure of a Radiation Fog Event in Nanjing

An extremely dense radiation fog event during 10-11 December 2007 was studied to understand its macro-micro-physics in relation to dynamic and thermodynamic structures of the boundary layer, as well as its structural evolution in conjunction with the air-surface exchange of heat and water vapor. The findings are as follows. The extreme radiation fog process was divisible into formation, development, mature, and dissipation phases, depending on microstructure and visibility. This fog event was marked by rapid evolution that occurred after sunrise, when enhanced surface evaporation and cold air intrusion led to a three order of magnitude increase in liquid water content （LWC） in just 20 minutes. The maximum droplet diameter （MDD） increased four-fold during the same period. The fog structure was two-layered, with the top of both the surface-layer and upper-layer components characterized by strong temperature and humidity inversions, and low-level jets existed in the boundary layer above each fog layer. Turbulence intensity, turbulent kinetic energy, and friction velocity differed remarkably from phase to phase： these features increased gradually before the fog formation and decreased during the development phase; during the mature and dissipation phases these characteristics increased and then decreased again. In the development and mature stages, the mean kinetic energy of the lower-level winds decreased pronouncedly, both in the horizontal and vertical directions.

Genotoxicity evaluation and a primary risk assessment of organic pollutants in the drinking water sources of Nanjing, China

An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In this study, the comet assay was conducted to investigate the genotoxicity to human body caused by organic concentrates in the drinking water sources of Nanjing City from Yangtze River of China, and health and ecology risk due to expose to these organic pollutants were evaluated with the multimedia environmental assessment system （MEAS）. For all the water samples, they were collected from four different locations in the drinking water sourcr samples, es of Nanjing City. The results of the comet assay showed that all the organic concentrates from the water samples could induce different levels DNA damages on human peripheral blood lymphocytes, and a statistically significant difference （p〈0.01） was observed compared with the solvent control, which demonstrated the genotoxicity was in existence. According to the ambient severity （AS） of individual compound, we had sorted out the main organic pollutants in the drinking water source of the four waterworks, and the results showed that there was some potential hazard to human body for all the source water, namely the total ambient severity （TAS） of health for each water source was more than 1. However, the TAS of ecology for each water source was less than 1, which indicated that it was safe to ecology. The results of this investigation demonstrate the application of the comet assay and the MEAS in aquatic environmental monitoring studies, and the comet assay found to be fast, sensitive, and suitable for genotoxicity monitoring programs of drinking water source.

Effects of Community Community Communication Technology(ICT) Usage on Community Satisfaction: Case Study in Nanjing, China

Future or smart community, which mainly refers to the development of community information and communication technology(ICT) platforms or devices, has received considerable attention from urban governments and scholars. However, only a few studies have been conducted to test the actual effects of using these community ICT platforms or devices on the community satisfaction of residents. Therefore, the present study conducts a survey in 40 communities in Nanjing, China and uses a mixed linear regression model to determine the relationship between community ICT usage and community satisfaction. Results indicate that residents with high-level community ICT usage are more satisfied with their community than those with low-level community ICT usage. Moreover, evident differences are observed regarding the influence of new commodity, old commodity and affordable housing communities in Nanjing. These findings are meaningful for the construction and development of future communities.

Characteristics and runoff volume of the Yangtze River paleo-valley at Nanjing reach in the Last Glacial Maximum

The stratigraphical cross-sections of the Yangtze River incised-valley near the No.l, No.3 and No.4 Nanjing Yangtze River bridges were established with respective bore date and documents. By ^14C age analysis of the samples of four drilling cores near the No.4 Bridge （to be built）, we can find that the time range of paleo-valley is dated in the LGM at a depth of-60 m to -90 m near Nanjing. It is also indicated that the deep incised-valley channel was narrow and the river flowed swiftly. The ancient Yangtze River deep channel presented partially and deeply incised features near the No.1 Bridge. According to previous publications, much research has been done on the main paleo-channel of the Yangtze River, but few results have been achieved on discharge estimation. In this paper, the incipient velocity and average veIocity of the LGM was calculated with Vc=4.60d^1/3h^1/6, Vc=1.281g（ 13.15. h /d95） √gd, V≈6.5u＊｜h/d90｜^1/6 etc., in terms of the river shape, sedimentary grain size and sequences near the No.3 and No.1 bridges. Moreover, the discharge in Nanjing reach of the Yangtze River during the LGM has been estimated to be around 12,000-16,000 m^3/s according to the relationship of discharge, velocity of flow and cross-section.