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The issues of housing and traffic in China's mega cities have become increasingly pressing problems, particularly for middle/low-income tenant workers. These tenants are from less advantaged socioeconomic backgrounds, which has resulted in a significant geographical separation between their workplace and their residence. Although a large number of studies have confirmed that built environment factors have a solid impact on residents' commuting distance, few studies have investigated the mechanism underlying the nonlinear influence on middle/low-income tenants. This paper aims to provide an in-depth analysis of the key factors and nonlinear influencing mechanism of the built environment on middle/low-income tenant workers' commuting distance by establishing a gradient-boosting decision tree model, using Beijing as an empirical case. The paper reveals three primary findings: (1) An important nonlinear relationship between the surrounding built environment and peoples' jobs–housing spatial proximity can be observed for those middle/low-income tenant workers who use slow and public modes of commuting. Specifically, the density of public transport stations, road networks, and workplaces, and the land use mix play a dominant role. (2) A limited effect of built environment factors can be found for the same group of tenant workers who choose cars as their mode of commuting. (3) The differences in self-selected commuting modes have a significant mediating effect on the relationship between the built environment and jobs–housing situation among middle/low-income tenant workers. Given this, effective policy guidance for residents' travel modes is necessary to optimize the built environment indicators to achieve the best effect. In addition, we should consider giving priority to the matching indicators such as land use mix and resident population density. Another possibility is to strengthen the connection to the public transport stations, which in turn can optimize the walkability in residential environments. [ABSTRACT FROM AUTHOR]

Focuses on the use of fetal-cell injections for patients with spinal cord injuries and amyotrophic lateral sclerosis in Beijing, China. Historical background of the unconventional treatment for neurological disease; Assessment of the effectiveness of the technique of injecting fetal cells into patients; Claims of Hongyun Huang who developed the treatment concerning the efficacy of the technique in improving the quality of life for people with spinal injuries.

The household is the basic unit of a residential community or building. High-resolution, long-term open data are necessary to help study residential electricity consumption, smart home technologies, and electricity flexibility technologies at household level. This paper introduces an IoT-based data collection platform (IDCP) consisting of gateways, sensors, and cloud servers. This platform can collect data on the occupant presence, indoor environment, window-opening states, and appliance electricity consumption simultaneously. This study deployed the IDCP in a single-family apartment in Beijing, China, and compiled a dataset, namely, CN-OBEE, including data on the per-minute occupant behavior, thermal environment, and appliance electricity use of the apartment for an entire year (from May 31, 2021, to May 31, 2022), and hourly meteorological data collected by the nearest national weather station during the same period. This dataset is the first detailed and publicly available occupant behavior and electricity use dataset for Chinese homes. As a regional feature, the dataset compiled by this study includes window-opening behavior and the use of split air conditioners (ACs). [ABSTRACT FROM AUTHOR]

This paper examines the effects of interventions to reduce air pollution during two international events on air quality in Beijing and its neighbor cities. Air quality data were gathered from China's Ministry of Environmental Protection, meteorological data from the China Meteorological Administration and economic data from the China Statistical Yearbook. The paper uses fixed-effect panel data models to empirically evaluate air quality improvement in Beijing and other affected cities before, during, and after the 2008 Olympic Games and the 2014 Asia-Pacific Economic Cooperation summit. Results show substantial improvement in air quality in Beijing and neighboring cities during the two events. However, some of the air quality improvement achieved reverted within a year after the games and within a week after the summit. Furthermore, the improvement achieved during the summit completely reverted and air quality deteriorated severely five days after the summit. It is also found that air quality in China, at least in the cities included in this study, gradually improved over the past 15 years or so. The findings suggest that sustainable interventions and incentive-based programs to reduce emissions from industry production and traffic are the key to maintaining the air pollution reduction achieved during the events. [ABSTRACT FROM AUTHOR]

Policy decision of curling refers to providing strategy suggestions for curling competition with the help of computers. Existing curling agents have achieved good results in the digital scenarios, but cannot make correct decisions when applied to actual competition and training scenes. In this paper, a strategies decision agent in the real scene has been proposed. The competition situation was acquired by a Situation-Aware Network and mapped by a Digital Extraction module. We designed Curling MCTS to explore the best strategy in continuous space. The effectiveness of our framework has been verified by experiments and evaluated by China's wheelchair curling team at China Disabled Sports Management Center. With the help of our system, China's wheelchair curling team trained effectively and won the championship in the XIII Paralympic Winter Games (2022, Beijing). In addition, a new curling target detection dataset was provided. [ABSTRACT FROM AUTHOR]

Ecological welfare performance is a measure of the relationship between input ecological resources and output welfare, and it reflects the sustainable development status of a region. In this paper, the environmental resource consumption and human development index of four areas (covering thirty provinces, autonomous regions, and municipalities) in China from 2019 to 2020 were predicted using the GM (1,1) model. The status and trend of sustainable development were evaluated using the Malmquist index and its decomposition index (catch-up effect and frontier e impact of movement). The corresponding regions' environmental resource consumption data and human development index from 2011–2018 were used for the analyses. The following results were obtained: (1) In terms of the catch-up effect. However, Beijing shows a greater technical efficiency than other regions with values less than 1, which is a drag on sustainable development. (2) Regarding the frontier movement effect, all regions' technical level has improved, and the frontier exhibits an upward trend. (3) According to the Malmquist total factor productivity index, the sustainability status has been continuously deteriorating in all regions, except for improvements in a few areas. (4) In terms of planning periods, the frontier movement effect positively contributed to sustainable development in all regions during the 12th and 13th Five-Year Plan periods; in other words, technological innovation promotes sustainable development. Except in Beijing, the catch-up effect had negative contributions. By combining the gray prediction model with the Malmquist index, the authors provide more in-depth insight into the sustainable development of four regions in China from ecological welfare performance. [ABSTRACT FROM AUTHOR]

The mountainous abandoned mine land is often distributed in the form of fragmented patches. Therefore, it can greatly promote the reuse value of abandoned mine land and relieve the pressure of land demand to realize the rational reuse of abandoned mine land based on the future land use structure and spatial layout of mountainous area. In this paper, optimization of the spatial structure of mountainous abandoned mine land reuse is realized through the system dynamics model and CLUE-S model. Mentougou district, Beijing, China is selected as the research area. System dynamics model with feedback functions is constructed to simulate land use structure from 2011 to 2025, which is taken as the quantitative constraint on spatial structure optimization. CLUE-S model with neighborhood analysis function is applied to simulate future land use spatial structure. The simulation result layer is superimposed with the abandoned mine land distribution layer and the optimized spatial structure of abandoned mine land reuse then is determined, checked by reuse suitability evaluation. The result shows that abandoned mine land can be fully optimized as other land use types according to demand, and the reuse directions are water conservancy facilities land, urban land, rural residential land, tourism land, garden land, woodland and grassland. The trend of abandoned mine land reuse tend to be consistent with land use types of neighboring patches. This study can provide theoretical reference for the practices of mountainous abandoned mine land reuse. [ABSTRACT FROM AUTHOR]

This paper provides an overview of the trend of generation, composition, and management of municipal solid waste, and estimates the carbon emissions arising from municipal solid waste management in Beijing. The correlation analysis conducted shows that the generation of municipal solid waste in Beijing has been growing steadily, showing high correlations ( r > 0.9) to the total GDP, per capita income, and the population. Food waste showed an increasing trend since 1990. Compared with the results of an investigation in 1990, ash and woodchips content in 2003 declined from 56% to 17%, while the percentage of paper and plastic increased from 10% to 29% over the same period. The calorific value of the municipal waste also increased, from 2,686 kJ/kg in 1990 to 4,667 kJ/kg in 2003, indicating that the waste is suitable for incineration. Currently, the source separation ratio of municipal waste is approximately 15%. About 94% of all the collected solid waste goes to the landfill while 4% is composted and 2% is incinerated. A moderate garbage collection fee is applied to both permanent and temporary residents in Beijing, but the willingness to pay for solid waste collection and treatment is still low. Under current treatment mode, the total amounts of carbon emission from waste disposal sites and incineration increased with the increase of municipal solid waste, from 29.8 Gg in 1990 to 84.5 Gg in 2003, including 83.3 Gg of CH4 and 22.0 Gg of CO2. The data availability and methodological challenges in monitoring the quantity and characteristics of municipal solid waste are discussed. [ABSTRACT FROM AUTHOR]

Using data from Beijing, this paper evaluates job accessibility for people living in affordable housing to job centers by public transit, including urban metro and bus. By comparing the middle and low-income group who mainly use public transit and higher income group who mainly travel by car, results show an accessibility gap for different modes of transportation as travel by public transit takes nearly double the amount of time as travel by car. While commuting time is closely linked to the location of the provided affordable housing, it is also dependent on the quality of local public transit service. Areas with substantial travel time differences between public transit and car travel reveal the weaknesses of public transit provision. Furthermore, average commuting time by both public transit and car from areas of affordable housing built after 2004 is much longer than that from previously built areas implying that low-income groups are being driven to more disadvantaged locations with time changes. In contrast to the classical job-housing mismatch hypothesis in U.S. cities, the mismatch model in Chinese cities is that while major job opportunities are still concentrated in the central city, affordable housing residents who rely on urban metro and bus are being moved further afield into distant suburban areas. The paper will provide the implication for affordable housing and transportation planning in Chinese cities in the future. Improving job accessibility by further establishment of urban metro system for this demographic will promote the urban economy and provide social welfare for the disadvantaged. [ABSTRACT FROM AUTHOR]

Background: Biogenic volatile organic compounds (BVOCs) play an essential role in tropospheric atmospheric chemical reactions. There are few studies conducted on BVOCs emission of dominant forest species in the Jing-Jin-Ji area of China. Based on the field survey, forest resources data and the measured standard emission factors, the Guenther model developed in 1993 (G93) was applied in this paper to estimate the emission of BVOCs from several dominant forest species (Platycladus orientalis, Quercus variabilis, Betula platyphylla, Populus tomentosa, Pinus tabuliformis, Robinia pseudoacacia, Ulmus pumila, Salix babylonica and Larix gmelinii) in the Jing-Jin-Ji area in 2017. Then the spatiotemporal emission characteristics and atmospheric chemical reactivity of these species were extensively evaluated. Results: The results showed that the total annual BVOCs emission was estimated to be 70.8 Gg C·year− 1, consisting 40.5 % (28.7 Gg C·year− 1) of isoprene, 36.0 % (25.5 Gg C·year− 1) of monoterpenes and 23.4 % (16.6 Gg C·year− 1) of other VOCs. The emissions from Platycladus orientalis, Quercus variabilis, Populus tomentosa and Pinus tabulaeformis contributed 56.1 %, 41.2 %, 36.0 % and 31.1 %, respectively. The total BVOCs emission from the Jing-Jin-Ji area accounted for 61.9 % and 1.8 % in summer and winter, respectively. Up to 28.8 % of emission was detected from Chengde followed by Beijing with 24.9 %, that mainly distributed in the Taihang Mountains and the Yanshan Mountains. Additionally, the Robinia pseudoacacia, Populus tomentosa, Quercus variabilis, and Pinus tabulaeformis contributed mainly to BVOCs reaction activity. Conclusions: The BVOCs emission peaked in summer (June, July, and August) and bottomed out in winter (December, January, and February). Chengde contributed the most, followed by Beijing. Platycladus orientalis, Quercus variabilis, Populus tomentosa, Pinus tabulaeformis and Robinia pseudoacacia represent the primary contributors to BVOCs emission and atmospheric reactivity, hence the planting of these species should be reduced. [ABSTRACT FROM AUTHOR]

This paper explores Technology Business Incubators (TBIs) and their chosen Business Incubation Models. The business models of TBIs have been largely ignored or seen as explained through stratification classifications (e.g. university incubator, virtual incubator etc.). Taking a qualitative approach, five next generation TBIs clustered in the Zhongguancun region of Beijing, the 'Chinese Silicon Valley', are analyzed. Framed in the resource-based view this work contributes to the literature through the exploration of: (1) The strategies implemented by next generation TBIs in China (2) The business models of these incubators (3) The fit between each incubator's business model and their respective strategy. Ultimately this study disentangles how the varying availability of resources and incubatees' ability to absorb these resources guide incubator strategy. [ABSTRACT FROM AUTHOR]

Beijing faces a serious problem of carbon emissions and the economic sectors are the main source of carbon emissions. Previous literatures have extensively focused on estimating the impact of carbon emissions of individual sector. Little attention has been paid to the multisectoral carbon emissions. In this paper, a multisectoral decomposition analysis was reported to explore the carbon emissions in Beijing. The emissions are decomposed into energy structure, energy intensity, economic structure (in industry), economic output, and population scale effects by the method of logarithmic mean Divisia index. Agricultural, industrial, construction, transportation, commercial, and other sectors are taken into consideration. The results show that population scale effect is the main factor for increasing carbon emissions in all sectors. The energy efficiency improvements are primarily responsible for the decrease in emissions in the industrial sector, while it increases emissions in construction, transportation, and commercial sectors. The economic output in agricultural and other sectors exerts a positive effect on emissions. In contrast, the energy structure effect only makes a minor contribution to the emission decrease in industrial, construction, commercial, and other sectors. [ABSTRACT FROM AUTHOR]

The ownership of electric vehicles, including plug-in electric vehicles (PEVs) and hybrid electric vehicles (HEVs), begins to be prevalent at present and poses as a promising way to alleviate environmental pollutions. However, the traditional method of environmental impact assessment is encountering challenges due to the large differences between conventional internal combustion engine vehicles (ICEVs) and electric vehicles. This paper proposes a novel SEA method for the penetration of electric vehicles at link level. An absorbing Markov chain model is formulated to represent the transition process among ICEVs, PEVs, and HEVs in the future, where PEV is an absorbing state. In addition, both HEV and PEV travelers are assumed to behave in the same manner as conventional ICEV travelers. As a result, the vehicle fleet composition is consistent with their market shares on each link. However, the three vehicle types are distinguished by their respective emissions rates. Therefore, the strategic environmental assessment can be worked out based on market penetration level and link traffic flows. For a given road network, transport system equilibrium is proposed to calculate link traffic flows. It is a four-step sequential model with feedback channel which can be solved by method of successive averages (MSA) effectively. For sustainable development, China plans to build a new city named Xiong'an nearby the capital Beijing. The strategic environmental assessment is conducted using the development of Xiong'an as an experimental study to demonstrate the effectiveness of proposed method. This research is very useful in urban planning with environmental constraints. [ABSTRACT FROM AUTHOR]

The article presents several references contributed by Marxists and non-Marxists in the International Congress of History of Science (ICHS) symposium titled as "Politically Engaged Scientists, 1920,1950: Science,Politics, Philosophy, History" in Beijing, on July 2005. The objective of the symposium is cited to draw discussions about the scientists who conferred to the construction of scientific and ideological networks related to politically activist approaches. The contributions include the introduction of Matt Stanley of the case of A. S. Eddington, the British astronomer and his known popularization of science in the 1920s. It also mentions the paper of Christian Fostner about David Bohm and his lack of political commitment in the public field.

Collaboration among industry, university, and research institution (IUR) is dialectically linked with regional resources and networks. As the best-known innovative region in China, Zhongguancun in Beijing is no exception. The purpose of this paper is to understand the innovation network of IUR collaboration in Zhongguancun, focusing on linkages between industry and university as well as public research institutes, a key mechanism for transfer and diffusion of academic research and knowledge. Starting from a qualitative analysis of the formation and development process of this network, we combine social network analysis and spatial analysis methods at firm level and reveal the temporal and spatial evolution of Zhongguancun IUR cooperative innovation network. The network has developed from a single driver relying on government-centered connections into a more diversified system based on government and market incentives. A set of large, medium and small radial sub-networks have become interwoven, resembling a hub-and-spoke spatial structure. [ABSTRACT FROM AUTHOR]

In order to improve the forecasting accuracy of atmospheric pollutant concentration, a prediction model of atmospheric PM2.5 and nitrogen dioxide (NO2) concentration based on support vector regression (SVR) is established. Quantum-behaved particle swarm optimization (QPSO) algorithm is used to select the optimal parameters influencing the performance of SVR. And in order to improve the problem that the fixed SVR model is difficult to adapt to the highly nonlinear process, a simple online SVR based on re-modeling method is proposed instead of the fixed one. According to hourly PM2.5 and NO2 concentrations and meteorological conditions from May 2014 to April 2015 in Wanliu Monitoring Station of Beijing in China, the experiment is carried out based on the data of 3 months. Meanwhile, PM2.5 concentration is predicted by three different prediction methods, including the recursive prediction method, direct prediction method, and online direct prediction method. The results show that the online direct prediction method is the most accurate in the three prediction methods. In addition, compared with original particle swarm optimization (PSO) algorithm, QPSO algorithm is tested more efficiently for the improvement of global search ability and robustness during the procedure of parameter selection. Moreover, the hybrid QPSO-SVR model proposed in this paper has higher prediction accuracy and less computational time compared with the PSO-SVR model, genetic algorithm (GA)-SVR model, and grid search (GS)-SVR model, which indicates reliability and effectiveness of the QPSO-SVR model in prediction of these two pollutant concentrations. [ABSTRACT FROM AUTHOR]

The effectiveness of national policies for air pollution control has been demonstrated, but the relative effectiveness of short-term emission reduction measures in comparison with national policies has not. Here we show that short-term abatement measures during important international events substantially reduced PM2.5 concentrations, but air quality rebounded to pre-event levels after the measures ceased. Long-term adherence to strict emission reduction policies led to successful decreases of 54% in PM2.5 concentrations in Beijing, and 23% in atmospheric nitrogen deposition in China from 2012 to 2020. Incentivized by "blue skies" type campaigns, economic development and reactive nitrogen pollution are quickly decoupled, showing that a combination of inspiring but aggressive short-term measures and effective but durable long-term policies delivers sustainable air quality improvement. However, increased ammonia concentrations, transboundary pollutant flows, and the complexity to achieving reduction targets under climate change scenarios, underscore the need for the synergistic control of multiple pollutants and inter-regional action. In response to the rebound of air pollution during large events in China, the authors propose that a combination of ambitious short-term measures and enduring long-term pollution control policies is a sustainable solution for improving air quality. [ABSTRACT FROM AUTHOR]

This study focuses on analyzing the provincial CO2 emission efficiency of China using data on energy consumption and carbon emissions from 2013 to 2019. Specifically, the game cross-equilibrium efficient frontier data envelopment analysis (DEA) approach, consisting of a game cross-efficiency model and a DEA fixed-sum output model, was proposed. In this method, CO2 is considered a fixed-sum undesirable output, and the decision-making units (DMUs) affect each other to achieve the efficiency result. The results show that: (1) CO2 emissions efficiency varied significantly between provinces during the study period, with Beijing performing the best and Ningxia the worst. (2) The overall national average CO2 emission efficiency showed a slow increasing trend over time. The eastern region performed best, followed by the northeastern, central, and western regions. (3) By comparing the existing DEA fixed-sum output methods, the CO2 efficiency obtained by our method, considering the DMU game relationship, is more acceptable. Based on these results, several policies and improvements were recommended to the provinces, such as reducing energy utilization in high-carbon emission industries. [ABSTRACT FROM AUTHOR]

Despite rapid urbanization, water use in Beijing Municipality decreased between the mid-1990s and 2006, reflecting decline in industrial and agricultural uses that countervailed increases in domestic consumption. This paper applies two models linking land and water use to estimate current levels of water use in Beijing. The first, a Markov chain approach, estimates land use change over time, applying water-use-to-land-use ratios to estimate current water usage. The second, a spatially disaggregated model that projects land use by county based on county characteristics, applies water-to-land ratios to estimate water use at a given point in time. While their estimates differ, both approaches strongly suggest that the recent trend of decreasing water use has ceased-water use increased between 2006 and 2010 and is likely to increase further. The result will be increased pressure on water resources and the need for greater attention to water management policies to achieve sustainability. [ABSTRACT FROM AUTHOR]

The aim of the paper is to estimate and assess residents' willingness to pay to improve air quality in the urban area of Beijing using the Contingent Valuation Method (CVM). The mean willingness to pay (WTP) for a 50% reduction of harmful substances in the air was 143 CNY per household per year, and the total WTP of the residents in the study area was 336 million CNY per year. As a proportion of household annual income, the mean WTP amounted to 0.7%. Four socio-economic variables were found to have significant impacts on residents' willingness to pay. The analysis results illustrated that WTP increases with income and education level, and decreases with household population and age. The willingness was larger for residents in the urban districts than those in the suburban districts. It was found that most of the protest bids lay on interviewees' incomplete perception of the values of environmental amenity. The influence of household income on people's willingness to pay illustrated in this study reflects a causal force of Beijing's transition to market economy that households created to have disposable income are more likely to care about environmental quality. The results of this study strike an optimistic note on the possibility of measuring the total economic value of environmental quality improvement by using the CVM in China. Suggestions on implication of the CVM for both academics and policy makers are provided in the paper. [ABSTRACT FROM AUTHOR]

Risk-related information regarding air pollution can help people understand the risk involved and take preventive measures to reduce health loss. However, the health benefits through these protective behaviors and the health threat of information inequality have not been systematically measured. This article reports the health gains and losses caused by the interaction of "air pollution—air pollution information—human", and studies the heterogeneity and impact of this interaction. Based on field investigations and transfer learning algorism, this study compiled the first nationwide city-level risk-related information (ERI) response parameter set in China. Then, we developed a Information-Behavioral Equivalent PM2.5 Exposure Model (I-BEPEM) model to project the health benefits caused by the impact of environmental risk-related information on residents' protective behaviors under different scenarios. The protective behavior led by air pollution risk information reduces 5.7% PM2.5-related premature deaths per year. With a 1% increase in regional ERI reception, PM2.5-related premature mortality decreases by 0.1% on average; If the level of information perception and behavioral protection in all cities is the same as that in Beijing, PM2.5-related premature deaths will decrease by 6.9% annually in China. Further, changing the air quality standard issued by China to the American standard can reduce the overall PM2.5-related premature deaths by 9.9%. Meanwhile, compared with men, other age groups and rural residents, women, older persons, and urban residents are more likely to conceive risk information and adopt protective behaviors to reduce the risk of premature death from air pollution. Air pollution risk information can significantly reduce people's health loss. Changing the real-time air quality monitoring information indicator standard to a more stringent level can quickly and effectively enhance this effect. However, the uneven distribution of this information in regions and populations has resulted in the inequality of health gains and losses. [ABSTRACT FROM AUTHOR]

An innovative approach of mean emission by vehicle type was used in this paper to assess the impact of new vehicle emission standards in Beijing, China during the period of 2000-2005. It was found that CO and NO emissions decreased by 48% and 23%, respectively, from Type O (before 2000) to Type I (year 2000) vehicles. The reductions from Type O to Type II (year 2002) vehicles were 85% and 73% for CO and NO, respectively. When all three types of vehicles (Types O, I and II) are combined, the annual per vehicle CO emissions decreased from 586 kg per vehicle per year in 2000 to 324 kg per vehicle per year in 2005, while that of NO decreased from 66.9 to 43.4 kg per vehicle per year, which was mainly resulted from the impact of stringent new vehicle emission standards implemented in years 2000 and 2002. However, the vehicle population increased by 70% during the same time period, which offset the impact of cleaner vehicles. Thus, the total vehicle emission decreased little for CO (885,000 tons in 2000, 837,000 tons in 2005) and even increased slightly for NO (101,000 and 112,000 tons in 2000 and 2005, respectively). The ambient concentrations of CO decreased significantly throughout 2000-2005, the same trend was not observed for NO. Correlation analysis (grey correlation and Pearson correlation) between the annual vehicle emissions and annual concentrations of CO, the annual NO emission and annual NO concentration indicated that the implementation of new vehicle emission standards was associated with the abatement of ambient CO and NO concentrations in Beijing. [ABSTRACT FROM AUTHOR]

Subalpine meadows in the Dongling Mountains (located at E115º26′-115º40′, N40º00′-40º05′) of Beijing, China are important for tourism and the provision of ecosystem services. However, because of poor management serious degradation has occurred on these subalpine meadows. The aim of this paper is to present a quantitative analysis of effects of tourism disturbance and topography on the status and diversity of montane meadow communities and to provide direction for improved management. Sixty quadrats of 2 × 2 m along 10 transects were set up to collect data on site characteristics and vegetation status. The relationships between community composition and structure, species diversity, and tourism disturbance and topographic variables were analyzed by multivariate methods (TWINSPAN and CCA). The results showed that eight meadow communities were identified by TWINSPAN. Most of them were seriously degraded. The first CCA axis identified an elevation and tourism disturbance intensity gradient, which illustrated that tourism disturbance and elevation were most important factors influencing meadow types, composition and structure. Some resistant species and response species to tourism disturbance were identified and can be used as indicator species of tourism disturbance. Species richness, heterogeneity and evenness were closely related to tourism disturbance and elevation. It is concluded that tourism disturbance must be controlled to enable grassland rehabilitation to occur in the meadows. Measures of effective management of the meadows were discussed. [ABSTRACT FROM AUTHOR]

Occurrence and fate of eight kinds of selected endocrine-disrupting compounds (EDCs) in three sewage treatment plants (STPs) of Beijing, China was investigated. These EDCs, composed of 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), bisphenol A (BPA), estrone (E1), 17 α-estradiol (17 α-E2), 17 β-estradiol (E2), estriol (E3) and 17 α-ethinylestradiol (EE2), in every step of STPs, were simultaneously analysed by gas chromatography/mass spectrometry after derivatisation. All the EDCs were detected in the influents of three STPs, and BPA was the most abundant compound. The concentrations of EDCs ranged from 36.6 ng/l of 17 α-E2 (STP C) to 1342.3 ng/l of BPA (STP B) in the influent sewages and from below limits of detection of E2 and E3 (STP C) to 142.5 ng/l of E1 (STP B) in the effluent sewages. The STPs could not remove alkylphenols effectively from the aqueous phase with less than 40% reduction. BPA decreased over 90%, and steroid estrogens achieved considerable reductions from 64.8% of E2 to 94.9% of E3. Generally, biological treatment was more effective in removing alkylphenols, BPA and natural estrogens from the aqueous phase than primary treatment. However, the synthetic estrogen, EE2, was mostly removed by the primary treatment with about 63.5% reduction. It is the first time that the concentration of 17 α-E2 in the sewage of China was reported in this paper. The compound might have a bearing with the waste effluents of dairy farms around urban area of Beijing. [ABSTRACT FROM AUTHOR]

Slope stability models traditionally use simple indicators of root system structure and strength when vegetation is included as a factor. However, additional root system traits should be considered when managing vegetated slopes to avoid shallow substrate mass movement. Traits including root distribution, length, orientation and diameter are recognized as influencing soil fixation, but do not consider the spatial and temporal dimensions of roots within a system. Thick roots act like soil nails on slopes and the spatial position of these thick roots determines the arrangement of the associated thin roots. Thin roots act in tension during failure on slopes and if they traverse the potential shear zone, provide a major contribution in protecting against landslides. We discuss how root traits change depending on ontogeny and climate, how traits are affected by the local soil environment and the types of plastic responses expressed by the plant. How a landslide engineer can use this information when considering slope stability and management strategies is discussed, along with perspectives for future research. This review encompasses many ideas, data and concepts presented at the Second International Conference ‘Ground Bio- and Eco-engineering: The Use of Vegetation to Improve Slope Stability—ICGBE2’ held at Beijing, China, 14–18 July 2008. Several papers from this conference are published in this edition of Plant and Soil. [ABSTRACT FROM AUTHOR]

In this paper, urban-rural temperature, relative humidity and vapour pressure differences at fixed hours in Beijing area were analyzed and compared. The data from one station with different observation surroundings and one rural station (0200, 0800, 1400 and 2000 hours local standard time (LST)) for the period 1971–2003 were used. The effect of urban on local temperature, relative humidity and vapour pressure were discussed. Results showed that the urban environment caused great increase in local temperature at 0200, 0800 and 2000 hours and small increase at 1400 hours. Also, the urban effect on humidity suggested that the urban environment can decrease relative humidity and vapour pressure at all fixed hours, while the urban-rural relative humidity differences are great at 2000 and 0200 hours and the urban-rural vapour pressure differences are great at 1400 and 2000 hours. The annual average temperature, relative humidity and vapour pressure difference between urban and rural are about 1.76°C, 6.3% and 1.5475 hpa during the period from 1981 to 1997, respectively. Results indicated that the urban effect on local temperature and humidity is significant in Beijing area. [ABSTRACT FROM AUTHOR]

In this paper, the attractors of turbulent flows in phase space are reconstructed by the time delay technique using observed data of atmospheric boundary-layer turbulence, which include high resolution temperature, humidity and three-dimensional wind speed measurements in Gansu province and Beijing, China. The correlation dimensions and largest Lyapunov exponents have been computed. The results indicate that all the largest Lyapunov exponents in different conditions of time, site and atmospheric stability are greater than zero. This means that the atmospheric boundary-layer turbulence system is really chaotic and has appropriate low-dimensional strange attractors whose dimension numbers range from 3 to 7 and vary with different variables (dynamical variables or non-dynamical variables) and atmospheric stability. Turbulent kinetic energy is first applied to reconstruct the attractor of turbulence, and is found to be feasible. [ABSTRACT FROM AUTHOR]

People's willingness to get vaccinated determines whether the campaigns against the COVID-19 pandemic can be successful in part. Considering the fact that both foreigners and its nationals are exposed to the risk of infection in China, the Chinese government has taken measures favorable to foreigners in terms of the vaccination, yet South Korean sojourners were reluctant to get China-developed COVID-19 vaccines. This study employed the trust in institutions and trust in media as a theoretical framework and seeks to analyze how these two affect South Korean sojourners' intention to get Chinese COVID-19 vaccines. 25 South Korean sojourners living in Beijing participated in semi-structured interviews. The results showed that the mistrust South Korean sojourners have in China's institutions and media, both traditional and social media, led to their reluctance to get Chinese COVID-19 vaccines. In addition, South Korean sojourners' higher interpersonal trust in their peers also influenced their willingness to get vaccines. This study further interpreted such results from the perspective of cultural traits and national properties. [ABSTRACT FROM AUTHOR]

To improve energy-saving management, the energy efficiency grade (EEG) was introduced by the Chinese government in the 2000s and mainly implemented for white goods (WGs) in early stages. However, due to the lack of actual statistics, how effective the promotion of high EEG WGs has been in China is still not clear. The China Energy Efficiency Grade (CEEG) of WGs dataset described here comprises (i) EEG-related data on 5 kinds of WGs at the regional (national, provincial) and household levels in China and (ii) predictions of future average EEG trends. By web crawling, retrieving and processing in SQL, the average EEG data weighted by sales in 30 provinces in mainland China from 2012 to 2019 are provided. Household WG survey data, including household information and average EEG, were collected by distributing questionnaires to 1327 households in Beijing, China. The CEEG dataset will facilitate the advancement of research on household energy consumption, household appliance consumer choice, and the assessment of energy efficiency-related policies. [ABSTRACT FROM AUTHOR]

Due to concealed initial symptoms, many diabetic patients are not diagnosed in time, which delays treatment. Machine learning methods have been applied to increase the diagnosis rate, but most of them are black boxes lacking interpretability. Rule extraction is usually used to turn on the black box. As the number of diabetic patients is far less than that of healthy people, the rules obtained by the existing rule extraction methods tend to identify healthy people rather than diabetic patients. To address the problem, a method for extracting reduced rules based on biased random forest and fuzzy support vector machine is proposed. Biased random forest uses the k-nearest neighbor (k-NN) algorithm to identify critical samples and generates more trees that tend to diagnose diabetes based on critical samples to improve the tendency of the generated rules for diabetic patients. In addition, the conditions and rules are reduced based on the error rate and coverage rate to enhance interpretability. Experiments on the Diabetes Medical Examination Data collected by Beijing Hospital (DMED-BH) dataset demonstrate that the proposed approach has outstanding results (MCC = 0.8802) when the rules are similar in number. Moreover, experiments on the Pima Indian Diabetes (PID) and China Health and Nutrition Survey (CHNS) datasets prove the generalization of the proposed method. [ABSTRACT FROM AUTHOR]

Influenza B virus circulates yearly with lower activity than that of influenza A virus in China. During winter 2017 to 2018, a sharp surge of influenza activity dominated by type B/Yamagata lineage virus caused unprecedented medical burden in Beijing. This research aimed to understand the underlying mechanism for this circulation and prepare for epidemics in the future. Sera samples collected from the patients in 2016–2017 and 2017–2018 flu seasons were tested for profiling hemagglutinin inhibition (HI) antibodies against both prevailing Victoria and Yamagata lineages of type B influenza viruses. It showed that the seroprevalence against both lineages of the virus in 2017–2018 winter was higher than that in 2016–2017, while no difference of the seroprevalence was observed between the two viruses. Meanwhile, significant elevated geometric mean titer (GMT) against both lineages of influenza B viruses was found in the specimens collected during 2017–2018 flu season than that from 2016 to 2017, suggesting the viruses might undergo antigenic changes. These results also suggested that lower GMT against both type B variants in 2016–2017 might serve as an immunological niche for the dominating of B/Yamagata virus in China during 2017–2018 winter season. Our findings have implication that there was a significantly elevation of HI antibodies to influenza viruses B in 2017–2018 than in 2016–2017. On the other hand, the low level of HI antibodies to both B/Y and B/V in 2016–2017 could contribute to the severe B/Y epidemic in 2017–2018 to some extent. [ABSTRACT FROM AUTHOR]

Historical and cultural districts are an important part of the urban heritage environment, reflecting the urban characteristics and carrying the core value of urban development. At present, most of the research on the vitality of historical and cultural districts mainly carries out quantitative evaluation from the two aspects of material space and time dimension, while the analysis on the value level is weakened, and the content of value type evaluation is also ignored. Value is the main factor affecting the vitality of historical and cultural districts, and it is also the core content to keep them alive. Therefore, this study takes nine historical and cultural districts of three types (cultural, commercial and residential) in Beijing, the capital of China, as examples to form a vitality evaluation framework with value as the evaluation goal, and select three indicators: historical value (including historical environment, cultural environment and spatial environment), use value (including communication environment, business environment and residential environment) and sustainable value (including educational environment, attraction and creativity), which correspond to the past, present and future of the heritage respectively. The literature summary method is used to get the evaluation content, the ranking analytic hierarchy process is used to determine the index weight, experts are invited to score, and the influence degree of each factor is comprehensively ranked and analyzed. Finally, it puts forward the evaluation system of historical and cultural districts. The framework can be used to collect expert opinions, conduct quantitative value evaluation, and adjust various indicators in practice before the protection strategy of historical and cultural districts is proposed. The results show that at present, Shichahai, Nanluoguxiang and Fuchengmennei have the highest vitality among the three types. The blocks that mainly embody cultural value have higher vitality than those that mainly embody commercial value and residential value. [ABSTRACT FROM AUTHOR]

Food recall is a major ingredient in food safety with existing literature focusing mainly on its direct impacts. Few studies focus on possible spillover effects. It is hypothesized that food recalls have a spillover effect on the recalled brand and purchase channel. As a test of this hypothesis, a 2-purchase channel by 3-recall strategy scenario experiment was conducted on spillover effects of a milk recall in Beijing, China. The results indicate that food-safety scares have significant negative impacts on consumers' purchase intention on the recalled brand and purchase channel, and the impacts are more significant for online than offline marketing. However, voluntary recalls by online firms help mitigate these negative effects and restore consumers' purchase intention more than offline voluntary recalls. An online food incident creates an issue of trust toward general online platforms. Online vendors should take greater care in guaranteeing food safety and actively take restorative actions such as voluntary recalls after a food safety incident. Results provide empirical evidence for industry organizations and governments to stipulate a strict food safety and incident resolution system for e-commerce. [ABSTRACT FROM AUTHOR]

The impact of environmental motivations on the individual's decisions regarding investments in energy efficiency and the adoption of energy-saving habits are analyzed for a representative sample of Chinese inhabitants from the larger Beijing area, replicating a comparative study on Western Europe. For the considered type of energy efficiency investments and daily energy-saving activities similarities and discrepancies between the two regions are discussed in regard to their sociocultural background as well as governmental regulations. The study provides empirical evidence that for Chinese environmental issues if all only play a tertiary role after monetary and regulatory incentives. The findings could suggest that in China policy programs aimed at raising environmental awareness and forming pro-environmental motivations might not lead to an increase in energy efficiency investments and daily energy-saving activities and the Chinese government's interests in this regard might be better served by implementing corresponding incentives via regulations. In the long-term. However, social peer pressure might affect a change in the Chinese mentality. [ABSTRACT FROM AUTHOR]

Scholars have speculated that the Chinese may be more reluctant to express their opinions strongly and that this may be reinforced if the odd number response format with a mid-point option of 'no opinion' or 'neither agree nor disagree' is provided. This may undermine the quality of survey data because less variances or even inaccurate information will be collected. This study provides empirical evidence from 532 mainland Chinese employees in Beijing to test this speculation. These employees were randomly assigned to complete either an odd number or even number response format questionnaire. In contrast to the speculation, in a wide variety of measures that are relevant to the area of organizational behavior (OB) and human resource management (HRM), it appears that the odd number response format does not show systematic differences when compared with the even number response format. This result holds even for some sensitive measures of personal beliefs, evaluation of and judgments about employing organizations, supervisors, and colleagues. Given the increasing number of studies surveying Chinese and other Asian respondents, we call for further research on this issue. [ABSTRACT FROM AUTHOR]

Chinese tone sandhi systems are often classified as left-dominant or right-dominant depending on the position of the syllable retaining the citation tone. An asymmetry exists between the two types of systems: left-dominant sandhi often involves rightward extension of the initial tone to the entire sandhi domain; right-dominant sandhi, however, often involves default insertion and paradigmatic neutralization of nonfinal tones. I argue that the extension of a tone to a larger domain may serve two markedness purposes: the reduction of tonal contours on a syllable and the reduction of pitch differences across syllable boundaries, both of which have a rightward directionality preference. The former is due to the durational advantage afforded by final lengthening; the latter is due to the universal preference for progressive tonal coarticulation. I show that a theory that formally encodes these preferences via intrinsic constraint rankings can predict the directional asymmetry noted above. [ABSTRACT FROM AUTHOR]

Tachinidae are one of the most speciose families of Diptera and the largest group of non-hymenopteran parasitoids. Little is known about their diversity, distribution patterns, and seasonal variation in most ecosystems. This study reports on tachinid flies collected by a Malaise trap over 73 weeks in Baihua Mountain Reserve, northern China, and investigates the patterns of local species richness and its temporal distribution. The most species-rich season was summer, but the majority of specimens were recovered in spring. A total of 755 tachinid specimens were collected, consisting of 144 species in 85 genera, comprising 26.5% of the species and 49.7% of the genera recorded from northern China. A total species richness of 243 was estimated, indicating that only a portion of the community of tachinid flies was collected at this location and suggesting that the diversity of tachinids might be underestimated across Beijing and northern China. This work is a first step in assessing patterns of tachinid diversity in China using quantitative sampling and establishes a baseline for comprehending the temporal and spatial diversity of these ecologically significant parasitoids. [ABSTRACT FROM AUTHOR]

Topographical variation is hypothesized to directly and indirectly influence social value orientations (SVOs) through the two channels of physical environment and urbanization. To examine the effects of topography on SVOs in urbanization, we conduct field surveys in mountainous, hilly and plains areas of Beijing, collecting sociodemographic information and SVOs. Our results demonstrate that higher proportions of proself people are found in plains and hilly areas than in mountainous areas, reflecting topographical differences in people's SVOs. Overall, our results suggest that a new social mechanism is necessary to direct people's social preferences toward prosociality when more people live in plains and hilly areas; otherwise, important social issues, such as air pollution, which require cooperation for solutions, might pose a danger in the future. [ABSTRACT FROM AUTHOR]

To what extent do China's linkages to the global economy translate into political influence in other countries? This topic is the focus of copious amounts of policy and scholarly attention in the USA and around the world. Yet without thoughtful conceptualization of key assumptions and creation of research designs that allow identification of mechanisms of potential influence, we cannot gain an accurate understanding of Chinese influence. How can we assess Beijing's intentions? Through what mechanisms—both intended and unintended—might influence arise, and under what conditions is influence most likely to occur? To what degree are Chinese companies agents of the state and therefore tools of economic statecraft? What factors condition how host countries react to economic ties with China? In this article, we explore existing scholarship on these questions, and assess promising directions for future research. [ABSTRACT FROM AUTHOR]

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Estimating truck emissions accurately would benefit atmospheric research and public health protection. Here, we developed a full-sample enumeration approach TrackATruck to bridge low-frequency but full-size vehicles driving big data to high-resolution emission inventories. Based on 19 billion trajectories, we show how big the emission difference could be using different approaches: 99% variation coefficients on regional total (including 31% emissions from non-local trucks), and ± as large as 15 times on individual counties. Even if total amounts are set the same, the emissions on primary cargo routes were underestimated in the former by a multiple of 2–10 using aggregated approaches. Time allocation proxies are generated, indicating the importance of day-to-day estimation because the variation reached 26-fold. Low emission zone policy reduced emissions in the zone, but raised emissions in upwind areas in Beijing's case. Comprehensive measures should be considered, e.g. the demand-side optimization. There lacks a method to measure the rapid changes of vehicle emissions. Here the authors proposed a big data approach 'TrackATruck', and their estimates using the new approach show that the heavy-duty trucks (HDT) emissions of primary cargo routes/terminals were underestimated by 2–10 times in proxy-based emission inventories. [ABSTRACT FROM AUTHOR]

In China, developing intelligent cities has become an irresistible trend of development in cities at present. Intelligent cities have been constructed in various regions. With the continuous implementation of intelligent cities, the evaluation index system has been gradually improved. Based on this, intelligent city evaluation algorithm based on analytic hierarchy process is studied. The evaluation model was firstly constructed, followed by the analysis of the analytic hierarchy process, and the analytic hierarchy process was applied to the evaluation of intelligent cities. Then, an empirical study of the algorithm was conducted in Fangshan District of Beijing as an example to explain the application of the algorithm. [ABSTRACT FROM AUTHOR]

Over the past 20 years, significant progress has been made in organic photovoltaics (OPVs) due to its advantages of being cost-effective, being lightweight, and having flexible manufacturability. The optical-active layer of OPVs consists of a p-type polymer as the donor and an n-type small molecule as the acceptor. An efficient design strategy of a polymer donor is based on an alternating electron-donating unit (D) and an electron-accepting unit (A). Among numerous electron-accepting units, an emerging annelated thiophene of benzodithiophenedione (BDD) has exhibited a distinguished photovoltaic performance because of its planar molecular structure, low-lying highest occupied molecular orbit (HOMO) level and good self-assembly property. In this review article, we summarize the most recent developments in BDD-based photovoltaic materials. Special attention is paid to the chemical structure-property relationships, such as the absorption, bandgap, energy levels, mobilities, and photovoltaic performances. The empirical regularities and perspectives on the future development of BDD-based photovoltaic materials are included. Photovoltaics: An organic solution Development of a polymer that has exciting potential for solar-energy conversion has been reviewed by researchers in China. Traditional solar cells are made using silicon, but their efficiency has not yet reached a level where they can compete with fossil fuels. In the last few decades, organic solar cells have emerged as an alternative, offering simpler fabrication and lighter, cost-effective and flexible devices. Lijun Huo from Beihang University, Beijing, and colleagues summarise recent progress in organic photovoltaic cells made using benzodithiophenedione (BDD) based polymeric donors. The authors review the properties of this kind of material that are key to optimising photovoltaic performance such as optical absorption, the electron energy levels, the charge mobility, the crystallinity and morphology. Careful control of these properties has enabled BDD-based devices to achieve power conversion efficiencies of over 15%. An emerging annelated thiophene of benzodithiophenedione (BDD) has exhibited its distinguished photovoltaic performance since its planar molecular structure, low-lying highest occupied molecular orbit (HOMO) level and well self-assembly property. In recent 7 years, BDD-based polymer donor have shown a rapid and incredible advancement by utilizing different acceptor materials. Considering the potentials of BDD-based materials, we summarize the most recent advances in the BDD-based photovoltaic materials and highlight the relations between BDD-based molecular structures and photovoltaic properties. [ABSTRACT FROM AUTHOR]

Solar-driven catalysis is a promising strategy for transforming CO2 into fuels and valuable chemical feedstocks, with current research focusing primarily on increasing CO2 conversion efficiency and product selectivity. Herein, a series of FeO–CeO2 nanocomposite catalysts were successfully prepared by H2 reduction of Fe(OH)3-Ce(OH)3 precursors at temperatures (x) ranging from 200 to 600 °C (the obtained catalysts are denoted as FeCe-x). An FeCe-300 catalyst with an Fe:Ce molar ratio of 2:1 demonstrated outstanding performance for photothermal CO2 conversion to CO in the presence of H2 under Xe lamp irradiation (CO2 conversion, 43.63%; CO selectivity, 99.87%; CO production rate, 19.61 mmol h−1 gcat−1; stable operation over 50 h). Characterization studies using powder X-ray diffraction and high-resolution transmission electron microscopy determined that the active catalyst comprises FeO and CeO2 nanoparticles. The selectivity to CO of the FeCe-x catalysts decreased as the reduction temperature (x) increased in the range of 300–500 °C due to the appearance of metallic Fe0, which introduced an additional reaction pathway for the production of CH4. In situ diffuse reflectance infrared Fourier transform spectroscopy identified formate, bicarbonate and methanol as important reaction intermediates during light-driven CO2 hydrogenation over the FeCe-x catalysts, providing key mechanistic information needed to explain the product distributions of CO2 hydrogenation on the different catalysts. Catalysis: Reclaiming carbon dioxide A nanomaterial that helps convert carbon dioxide to more useful chemicals has been developed by researchers in China. One potential method is to convert the carbon dioxide into carbon monoxide using a reaction known as reverse water-gas shift, and then use further reactions to convert this into fuel, or produce useful chemicals such as methanol or methane. This reaction normally requires high temperatures, and a catalyst is required to make the conversion efficient at lower, more practical temperatures. Tierui Zhang from the Technical Institute of Physics and Chemistry in Beijing and co-workers developed a nanocomposite based on iron and cerium with excellent performance in converting carbon dioxide into carbon monoxide with hydrogen only under light irradiation. This result indicates the potential of solar-driven catalysis for transforming carbon dioxide into fuels. A series of FeO-CeO2 nanocomposite catalysts (FeCe-x) were successfully fabricated by hydrogen reduction of hydroxide precursors at temperatures (x) between 200–600 °C. A FeCe-300 catalyst with a Fe:Ce ratio of 2-1 exhibited excellent performance for photothermal CO2 hydrogenation to CO (CO selectivity = 99.87%, CO production rate 19.61 mmol h−1 gcat−1, excellent stability). The FeO phase was effective in promoting the reverse water-gas shift (RWGS, CO2 + H2 → CO + H2O). Catalysts prepared at higher reduction temperatures contained both Fe0 and FeO, with the Fe0 catalyzing the Sabatier reaction (CO2 + 4H2 → CH4 + 2H2O) and thus lowering FeCe-x catalyst selectivity to CO. [ABSTRACT FROM AUTHOR]

The article introduces the special issue of the periodical which contains extended and revised versions of the majority of papers presented at the Minisymposium "Stability Behavior of Thin-Walled Structures" within the Sixth World Congress of Computational Mechanics which was held in Beijing, China from Septemer 5-10, 2004. The issue gives some insight into numerical simulations of the load carrying behavior of thin-walled structures especially of thin shells.

The Beijing-Tianjin-Hebei region experienced the most rainfall in 1994 and the least rainfall in 1997 during the last 20 years. Utilizing the Weather Research and Forecasting (WRF) model coupled with a single-layer urban canopy model (UCM), we investigate the possible effects of urbanization on summer precipitation under different climate backgrounds using the two extreme years. By comparing the results of control and sensitivity runs, we find totally different effects in the 2 years. In 1994, the rainfall and rainfall frequency decrease in most areas due to urbanization, and decreases in the rainfall intensity occur in urban areas of Beijing, Tangshan, and Shijiazhuang. In 1997, the rainfall, rainfall frequency, and intensity are reduced in southwest of Beijing-Tianjin-Hebei, while the change is opposite in northeast. Urbanization alters the diurnal distribution of rainfall, the energy budget, and the water vapor content in the atmosphere. Due to the decrease in city evaporation and transpiration, the surface latent heat flux is reduced. The water vapor mixing ratio in urban area decreases apparently from surface to 850 hPa, while it increases from 850 to 600 hPa. Overall, the reduction of water vapor mixing ratio in 1994 is more than that in 1997, which implies that the “dry island effect” caused by urbanization is stronger in the wet year than that in the dry year. Results also show that the inhibition (enhancement) of deep convection may explain the modification of precipitation. [ABSTRACT FROM AUTHOR]

A direct comparison of urban and rural surface energy balances, as well as a variety of other variables including incoming shortwave/longwave radiation and aerosol optical depth, is conducted for the Beijing metropolitan area. The results indicate that, overall, the urban area receives a smaller amount of incoming shortwave radiation but a larger amount of incoming longwave radiation. However, comparisons in the aerosol optical depth and cloud fraction at the two locations suggest that neither aerosol optical depth nor cloud fraction alone can explain the difference in the incoming shortwave radiation. The urban-rural differences in the incoming longwave radiation are unlikely to be caused by the presence of more abundant greenhouse gases over the urban area, as suggested by some previous studies, given that water vapor is the most dominant greenhouse gas and precipitable water is found to be less in urban areas. The higher incoming longwave radiation observed over the urban area is mostly likely due to the higher temperatures of the ambient air. The urban area is also found to always produce higher sensible heat fluxes and lower latent heat fluxes in the growing season. Furthermore, the urban area is associated with a larger amount of available energy (the sum of sensible and latent heat fluxes) than the rural area, except in May and October when evapotranspiration in the rural area significantly exceeds that in the urban area. This study provides observational evidence of urban-rural contrasts in relevant energy-balance components that plausibly arise from urban-rural differences in atmospheric and land-surface conditions. [ABSTRACT FROM AUTHOR]

Mining has been carried out upstream of Miyun Reservoir, Beijing, for several decades, and has caused metal emissions to the environment, threatening human health. We conducted a soil survey to assess metal contamination in this area and to determine distribution of heavy metals in the particle size. We attempted to determine the possible sources of the metals and the significance of metals in the fine particle fractions to soil risk assessments. Thirty-four soil samples were collected, and eight samples were partitioned into seven size fractions. Most of the metal concentrations in the soils were higher than the background levels in Beijing, and the metal concentrations and total organic matter (TOC) contents generally increased as the particle size decreased. Each metal except Hg significantly positively correlated with the TOC. The metals in the coarse-grained soils were mainly derived from parent materials, but the metals in the fine fractions were mostly anthropogenic. Statistical analyses showed that there were three metal sources: Cd, Cu, Hg, Pb, and Zn had anthropogenic sources; Co, Cr, Ni, and V had mixed anthropogenic and natural sources; and As and Be had natural sources. The trace metals were primarily in the clay and fine silt fractions, and they might pose health risks through the inhalation of resuspended soil particles (PM10 and PM2.5). The elevated accumulation factors, enrichment factors, and ecological risk indices for the metals in the fine fractions suggest that risk assessments should be based on the fine particle size. [ABSTRACT FROM AUTHOR]

A time-lagged ensemble method is used to improve 6-15 day precipitation forecasts from the Beijing Climate Center Atmospheric General Circulation Model, version 2.0.1. The approach averages the deterministic predictions of precipitation from the most recent model run and from earlier runs, all at the same forecast valid time. This lagged average forecast (LAF) method assigns equal weight to each ensemble member and produces a forecast by taking the ensemble mean. Our analyses of the Equitable Threat Score, the Hanssen and Kuipers Score, and the frequency bias indicate that the LAF using five members at time-lagged intervals of 6 h improves 6-15 day forecasts of precipitation frequency above 1 mm d and 5 mm d in many regions of China, and is more effective than the LAF method with selection of the time-lagged interval of 12 or 24 h between ensemble members. In particular, significant improvements are seen over regions where the frequencies of rainfall days are higher than about 40%-50% in the summer season; these regions include northeastern and central to southern China, and the southeastern Tibetan Plateau. [ABSTRACT FROM AUTHOR]

In order to investigate the metal distribution, speciation, correlation and origin, risk assessment, 86 surface soil samples from the catchment area around the Miyun Reservoir, Beijing, including samples from gold and iron mine areas, were monitored for fractions of heavy metal and total contents. Most of the metal concentrations in the gold and iron mine soil samples exceeded the metal background levels in Beijing. The contents of most elements in the gold mine tailings were noticeably higher than those in the iron mine tailings. Geochemical speciation data of the metals showed that the residual fraction dominated most of the heavy metals in both mines. In both mine areas, Mn had the greatest the acid-soluble fraction (F1) per portion. The high secondary-phase fraction portion of Cd in gold mine samples indicated that there was a direct potential hazard to organisms in the tested areas. Multivariate analysis coupled with the contents of selected metals, showed that Hg, Pb, Cr, and Ni in gold mine areas represented anthropogenic sources; Cd, Pb, and Cr in iron mine areas represented industrial sources. There was moderate to high contamination of a few metals in the gold and iron soil samples, the contamination levels were relatively higher in gold mine than in iron mine soils. [ABSTRACT FROM AUTHOR]