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In recent years, China's advanced light sources have entered a period of rapid construction and development. As modern X-ray detectors and data acquisition technologies advance, these facilities are expected to generate massive volumes of data annually, presenting significant challenges in data management and utilization. These challenges encompass data storage, metadata handling, data transfer and user data access. In response, the Data Organization Management Access Software (DOMAS) has been designed as a framework to address these issues. DOMAS encapsulates four fundamental modules of data management software, including metadata catalogue, metadata acquisition, data transfer and data service. For light source facilities, building a data management system only requires parameter configuration and minimal code development within DOMAS. This paper firstly discusses the development of advanced light sources in China and the associated demands and challenges in data management, prompting a reconsideration of data management software framework design. It then outlines the architecture of the framework, detailing its components and functions. Lastly, it highlights the application progress and effectiveness of DOMAS when deployed for the High Energy Photon Source (HEPS) and Beijing Synchrotron Radiation Facility (BSRF). [ABSTRACT FROM AUTHOR]

Video-based ship object detection has long been a popular research issue that has received attention in the water transportation industry. However, in low-illumination environments, such as at night or in fog, the water environment has a complex variety of light sources, video surveillance images are often accompanied by noise, and information on the details of objects in images is worsened. These problems cause high rates of false detection and missed detection when performing object detection for ships in low-illumination environments. Thus, this paper takes the detection of ship objects in low-illumination environments at night as the research object. The technical difficulties faced by object detection algorithms in low-illumination environments are analyzed, and a dataset of ship images is constructed by collecting images of ships (in the Nanjing section of Yangtze River in China) in low-illumination environments. In view of the outstanding performance of the RetinaNet model in general object detection, a new multiscale feature fusion network structure for a feature extraction module is proposed based on the same network architecture, in such a way that the extraction of more potential feature information from low-illumination images can be realized. In line with the feature detection network, the regression and classification detection network for anchor boxes is improved by means of the attention mechanism, guiding the network structure in the detection of object features. Moreover, the design and optimization of the augmentation of multiple random images and prior bounding boxes in the training process are also carried out. Finally, on the basis of experimental validation analysis, the optimized detection model was able to improve ship detection accuracy by 3.7% with a limited decrease in FPS (frames per second), and has better results in application. [ABSTRACT FROM AUTHOR]

The Soochow University Beamline, located at the National Synchrotron Radiation Laboratory in China, is a Soft X-ray beamline designed for studying energy-related materials and devices. It operates in the energy range of 45 eV–1100 eV and is specifically tailored for investigating Li, B, C, N, O, F K-edges, and most L-edges of transition metals. The beamline offers various capabilities, including X-ray absorption, photon in photon out, and in situ/operando studies of energy materials and devices in gas/liquid environments. It has been successful in producing high-quality research papers and is open to users worldwide. The beamline is a collaborative effort between Soochow University and the National Synchrotron Radiation Laboratory, with funding from Soochow University. It is the first synchrotron radiation beamline in China to be funded by a university. [Extracted from the article]

It is extremely important to accurately estimate reliability and lifetime of Bioregenerative Life Support System (BLSS) for its proper design, building and operation. However, this problem remains unsolved due to data deficiency of long-period prototype experiments. In this paper, the first ground-based experimental prototype of BLSS in China, Lunar Palace 1 (LP1), was selected as representative to estimate the reliability and lifetime of BLSS, because the number and time of each unit failure of LP1 was accurately recorded during the 370-day closed human experiment of LP1. Based on these time-series data, failure number probability distribution function of each unit and overall LP1 were formulated through parameter estimation and composite probability distribution function derived from units' series and parallel connection. Then, the influence of each unit failure on overall BLSS reliability and lifetime was determined correspondingly through sensitivity analysis and Monte Carlo simulations. Finally, the numerous pseudo-random numbers obeying the overall failure probability distribution function of LP1 were generated to estimate the reliability and lifetime of BLSS through maximum likelihood estimation and Monte Carlo simulations. The results demonstrate that the failure possibility of five units, water treatment unit, mineral element supply unit, LED light source unit, atmosphere management unit and temperature and humidity control unit have greater impact on reliability and lifetime of BLSS, and the mean lifetime of BLSS was 19112.37 days (about 52.4 years) with 95% confidence interval of [17367.11, 20672.68] days (about [47.58, 56.64] years) under normal operation and maintenance of BLSS. This research can lay a theoretical foundation for design, building and operation of BLSS with high reliability and long lifetime in the future. • Number and time of each unit failure in the 370-day closed human experiment of Lunar Palace 1 (LP1). • Failure number probability distribution function of each unit and overall LP1. • Sensitivity of LP1's reliability to each unit failure probability. • Generation of peculiar pseudo-random numbers by Monte Carlo simulations. • Mean lifetime of BLSS was 19112.37 days under normal operation and maintenance. [ABSTRACT FROM AUTHOR]

With the rapid development of population and urbanization and the progress of lighting technology, the influence of artificial light sources has increased. In this context, the problem of light pollution has attracted wide attention. Previous studies have revealed that light pollution can affect biological living environments, human physical and mental health, astronomical observations and many other aspects. Therefore, organizations internationally have begun to advocate for measures to prevent light pollution, many of which are recognized by the International Dark-Sky Association (IDA). In addition to improving public awareness, legal protections, technical treatments and other means, the construction of Dark Sky Reserves (DSR) has proven to be an effective preventive measure. So far, as a pioneer practice in this field, the IDA has identified 11 DSRs worldwide. Based on the DA requirements for DSRs, this paper utilizes NPP-VIIRS nighttime light data and other multi-source spatial data to analyze possible DSR sites in China. The land of China was divided into more than ten thousand 30 km × 30 km fishnets, and constraint and suitable conditions were designated, respectively, as light and cloud conditions, and scale, traffic and attractiveness conditions. Using a multiple criteria evaluation, 1443 fishnets were finally selected as most suitable sites for the construction of DSRs. Results found that less than 25% of China is not subject to light pollution, and less than 13% is suitable for DSR construction, primarily in western and northern areas, including Tibet, Xinjiang, Qinghai, Gansu and Inner Mongolia. [ABSTRACT FROM AUTHOR]

The creation of lightscapes in colleges and universities are of great significance in enhancing the perception of the campus environment, improving physical and mental health, and shaping humanistic connotations. This research aims to examine lightscape perceptions and impacts of different campuses. At Chongqing University A and B Campuses, lightscape walking experiments, subjective questionnaires, objective luminance measurements, and HDR picture processing were used to examine lightscape perception and factors. The relevance and differences in the perception of circadian lightscapes in the two campuses were analyzed using SPSS software. The study found: (1) natural lightscapes such as sky light, cloud shadow, and lake water reflection were the most popular during the daytime, while artificial lightscapes, such as decorative lighting of buildings, were positively evaluated at night; (2) the frequency of visits by a crowd directly impacts the ambiance of the environmental area; (3) males showed strong emotional awareness and social interaction skills in daytime, leading to increased social activity and stronger emotional responses, but no differences in nighttime; (4) optimal nighttime luminance enhances the overall perception satisfaction of the illumination; (5) the amount and arrangement of outdoor space, vegetation, minor landscape design, and service facilities all affect the perception of circadian lightscapes. In conclusion, design concepts and proposals of landscapes were suggested to optimize college and university lightscapes. [ABSTRACT FROM AUTHOR]

By using measured data of the research class IDMP station, a subset of three sky types and their probability of occurrence has previously been established to represent sky conditions of Hong Kong. This was dubbed the Hong Kong Representative Sky (HKRS). The HKRS allows a better prediction of daylight on the vertical surfaces of buildings than the CIE Overcast Sky. The HKRS was still a static representation. This paper investigates the possibility of using the weather predictions of the observatory to establish dynamically the HKRS. A methodology is proposed, and the results indicate that the approach is feasible. It is established that the weather prediction information issued by the Hong Kong Observatory (HKO) provides a reliable means for estimating probabilities of the sky types at a particular moment. By using this information, a better prediction of vertical sky component (VSC) on building surfaces, with a reduction of 20-30% mean absolute error, can be achieved. Engineers and architects may use this more accurate information to design more dynamically. [ABSTRACT FROM AUTHOR]

The Chinese real estate industry has experienced rapid growth since China's economic reform. Along with a booming industry, a third of purchased lands were left undeveloped in the last decade. Knowledge of real estate development time lags between land being purchased and property being occupied can enable policymakers to produce more effective policies and regulations to guide the real estate industry and sustain economic development and social welfare. This paper presents an innovative method to estimate provincial land development time lags in China using DMSP/OLS NTL imagery and real estate statistical data. The results showed that real estate development time lag was common in China during 2000-2010. More than half of the study sites showed development time lags of three years or longer. An Increment of Developed Pixels (IDP) index was established to outline yearly land development completions in China between 2000 and 2010. A Comprehensive Real Estate Price Index (CREPI) was created to explore the causes of the time lags. A strong and positive correlation was found between the real estate development time lags and CREPI values (with r = 0.619, n = 31, p < 0.0005). The results indicated that the land development time lag during the study period was positively correlated to the activity of the local real estate market, the price trend of land and housing properties, and the local economic situation. The results also proved that with the support of statistical data the DMSP/OLS NTL image could offer an economically efficient and reliable solution to estimate the time lag of real estate development. [ABSTRACT FROM AUTHOR]

The Southern Advanced Photon Source (SAPS), is a mid-energy ultra-low emittance ring-based light source proposed to be built adjacent to the China Spallation Neutron Source. Due to the capability of the hybrid-MBA (H-MBA) lattice to simultaneously realize excellent nonlinear performance and ultra-low emittance, a preliminary design has been designed for the SAPS based on modified H-MBAs where ultra-low emittance unit cells are combined therein to reach an emittance of 31.8 pm rad. Recently, a higher current is pursued to reach higher flux and brightness. To avoid the energy spread widening caused by microwave instability (MWI) at a higher current, it is particularly important to improve the MWI threshold. In this paper, we study the correlation between the lattice parameters and the MWI threshold. It is found that the circumference and momentum compaction factor are critical parameters in lattice design to improve the MWI threshold. By reducing the circumference from 1080 m to 810 m and raising the momentum compaction factor by nearly 2 times, the MWI threshold is significantly increased, resulting in an increase in the beam current from 200 mA to 400 mA. Furthermore, the emittance is reduced to 26.3 pm rad and the corresponding DA and MA meet the requirements of on-axis swap-out injection. [ABSTRACT FROM AUTHOR]

• The principle of the absolute hydrostatic leveling system as a means to establish online height datum is proposed. • A non-contact absolute hydrostatic level is designed. • Based on precise measurement of liquid depth, an absolute calibration of the level with an accuracy of 0.031 mm can be achieved. • The validation scheme of AHLS and absolute height accuracy is designed and 2-point AHLS can achieve absolute height with an accuracy of no less than 0.05 mm within a 10 m range. The fourth generation light source HEPS under construction in China demands higher alignment accuracy. However, it is difficult to improve height accuracy based on the overlap method of geometric and tracker leveling. Based on the study of hydrostatic leveling systems for ground settlement monitoring, this paper proposes a new method, Absolute Hydrostatic Leveling System (AHLS), for establishing height datum. The principle of establishing height datum for AHLS is described in detail, and it is emphasized that absolute calibration of the level is crucial for implementing this plan. A set of absolute calibration methods for non-contact absolute hydrostatic level is proposed, including measuring key dimensions of the level and precise measurement of liquid depth. The absolute calibration accuracy reaches 0.031 mm. The height accuracy of validating an AHLS between two points within 10 m using a laser tracker is more than 0.05 mm. The results demonstrate the feasibility of using AHLS to establish absolute height datum with high precision. With this method, the absolute height of each point can be obtained independently without any accumulated errors, allowing the establishment of height datum with high precision on a large scale. This approach can be used in the next generation of accelerator devices and also represents a novel method for achieving high-precision vertical monitoring. [ABSTRACT FROM AUTHOR]

Satellite-based PM2.5 estimation is an effective means to achieve large-scale and long-term PM2.5 monitoring and investigation. Currently, most of methods retrieve PM2.5 from satellite-derived aerosol optical depth (AOD) or top-of-atmosphere reflectance (TOAR) during daytime. A few algorithms are also developed to retrieve nighttime PM2.5 from the satellite day–night band and the accuracy is greatly limited by moonlight and artificial light sources. In this study, we utilize the properties of absorption pollutants in infrared spectrum to estimate PM2.5 concentrations from satellite infrared data, thus achieve the PM2.5 estimation in both day and night. Himawari-8 infrared bands data are used for PM2.5 estimation by a specifically designed neural network and loss function. Quantitative results show the satellite derived PM2.5 concentrations correlates with ground-based data well with R2 of 0.79 and RMSE of 15.43 μg · m−3 for hourly PM2.5 estimation. Spatiotemporal distributions of model-estimated PM2.5 over China are also analyzed, and exhibit a highly consistent with ground-based measurements. Dust storms, heavy air pollution and fire smoke events are examined to further demonstrate the efficacy of our model. Our method not only circumvents the intermediate retrievals of AOD, but also enables consistent estimation of PM2.5 concentrations during daytime and nighttime in real-time monitoring. [ABSTRACT FROM AUTHOR]

To ensure sufficient daylight in rooms, daylight performance metrics are the basic references to guide building design or to benchmark a building against another in terms of daylighting in a room. Daylight factor (DF) is the most commonly accepted daylight performance metric, but it has limitations in evaluating the daylighting of a room space in a real daylight climate, as defined under CIE standard overcast sky, while daylight autonomy (DA) is a climate-based performance metric which takes into consideration the regional daylight climate. Based on long-term continuous measurements of daylight illuminance in a test room under real climate, combined with scale model tests under an artificial sky and computational simulations, the quantitative relationship between monthly average daylight illuminance, DF and DA are holistically analyzed in this paper. The result shows that a monthly average daylight illuminance above 300 lx in a room located in Canton requires a DF of no less than 1.8% for north-facing space. Finally, the depth of DA 300lx [50%] daylit area for four cardinal directions was proposed in comparison with DF. [ABSTRACT FROM AUTHOR]

In the fourth-generation storage ring light sources (4GLSs), associated with the extremely strong nonlinearities inherent in the multi-bend achromat design, the dynamic acceptance is usually small and it is difficult to implement traditional off-axis local-bump injection. To release the requirement on dynamic acceptance, on-axis longitudinal injection schemes have been explored. In this paper, we present a multi-objective optimization of longitudinal injection with a multi-frequency RF system, based on the parameters of the Southern Advanced Photon Source, a 4GLS proposed in China. We show that by treating the optimal bunch lengthening condition as an optimizing objective rather than a condition that must be satisfied, a plethora of feasible candidate solutions can be found, showing different trade-offs among multi-objectives. From these candidate solutions, one can find an optimal RF parameter setting that is most adapted to a specific 4GLS physics design and the available technical level of injection kicker. Especially, it would be feasible to realize longitudinal injection within a static bucket enabled by a double-frequency RF system, suggesting an attractive longitudinal injection option for 4GLSs. [ABSTRACT FROM AUTHOR]

Korean pine (Pinus koraiensis Sieb. et Zucc.), as the main tree species in northeast China, has important economic and ecological values. Currently, supplementary light has been widely used in plant cultivation projects. However, the studies about different supplementary light sources on the growth and development of Korean pine are few. In this study, the one with no supplementary light was used as the control, and two kinds of light sources were set up: light-emitting diode (LED) and incandescent lamp, to supplement light treatment of Korean pine. The spectrum and intensity of these two light sources were different. The results showed that the growth and physiological–biochemical indicators were significantly different under different supplementary light treatments. The biomass of supplementary light treatment was significantly lower than the control. Compared with the control, IAA and GA were lower, and JA, ABA, ZT, and ETH were higher under supplementary light conditions. Photosynthetic parameters in supplementary light conditions were significantly lower than the control. Supplemental light induces chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid accumulation. From RNA-seq data, differentially expressed genes (DEGs) were observed in all the comparison groups, and there were 487 common DEGs. The expression levels of DEGs encoding transcription factors were also changed. According to GO and KEGG analysis, the plant hormone signal transduction, circadian rhythm-plant, and flavonoid biosynthesis pathways were the most enriched. These results provided a theoretical basis for the response of Korean pine to different supplementary lights. [ABSTRACT FROM AUTHOR]

Artificial light owns a rapid-expanding pattern, which may disrupt the sleep behaviors of birds roosting in illuminated urban areas. Whether the birds' sleep would variably be affected by light with different wavelengths or intensities has not been broadly explored, and the species in Eastern China have rarely been investigated. The study chose Chestnut buntings that are a common migratory species flying via Eastern China as the subjects and investigated their sleep in response to five light spectrums at three ecologically relevant intensities. It shows that artificial light mainly delayed sleep onset, reduced sleep duration and increased frequency of awakenings, which to the largest degrees resulted in a 3-h delay of sleep onset, 25% reduction of sleep and 0.31 times/h more nocturnal awakenings. Awakening time was delayed at higher light intensity while being advanced in dimmed light. The effect of light spectrums overall ranked from the most to the least as 510 nm green, 580 nm yellow or white, and 470 nm blue or 620 nm orange light; the sleep parameters were affected more with higher light intensities. The study highlights the potential of adjusting spectral compositions of light source to mitigate the disturbance of artificial light to avian sleep. [ABSTRACT FROM AUTHOR]

A synchrotron light source is familiar to many researchers. Biologists use it to determine structures of proteins and other biomacromolecules; material scientists use it to analyze internal structures of different materials; physicists use it to explore the basic matter states; and physicians use it to perform medical imaging. A high-performance synchrotron light source is often the workhorse supporting a prosperous multi-disciplinary research center. In China, that is the Shanghai Synchrotron Radiation Facility (SSRF). Since its opening to users in 2009, SSRF has bred many significant scientific achievements and laid the foundation for the Shanghai Zhangjiang Cluster of Big Science Facilities. On 3 August 2021, National Science Review (NSR) interviewed Professor Zhentang Zhao, Director of the SSRF Science Center and vice president of the Shanghai Advanced Research Institute, Chinese Academy of Sciences (CAS). Prof. Zhao introduced the construction and development of the synchrotron light source and X-ray free electron laser facilities in Shanghai, as well as how SSRF experiences may be valuable for big science facilities and centers now under construction in China. [ABSTRACT FROM AUTHOR]

Abstract: The Shanghai Synchrotron Radiation Facility (SSRF) is a new third generation storage ring based light source located at Zhangjiang High-Tech Park Shanghai China. The storage ring started commissioning in December 2007. During early commissioning, the fast ion instability (FII) was observed when multi-bunches were injected, which was strongly dependent on the vacuum pressure and filling patterns. In this paper, a weak–strong simulation code is employed to simulate the FII in the SSRF storage ring for various filling patterns and gas pressures. In addition, experimental study on cures of the FII has also been carried out. The results show that introducing gaps in between the bunch trains and increasing the ring chromaticity are very effective to suppress the growth of the FII. [Copyright &y& Elsevier]

Lighting energy consumption occupies a large proportion in the building electricity consumption. It cannot only save energy, but also reduce the uneven and constant illumination of the working face, which makes full use of the natural lighting and combines with the intelligent lighting control. An office building in Zhengzhou of China has been selected as an example for analyzing the climatic factors that influence building daylighting and the factors of the building itself, the illuminance of working faces in different sky models and at different times has been simulated and calculated to analyze the illuminance variation law in the direction of room depth and parallel direction of side Windows. Partition and point combined constant illumination control strategy for the lamps in different areas has been put forward and realized by BP neural network algorithm. By controlling the dimming of artificial light source and adjusting the curtain opening degree intelligently, uniform and constant illumination has been achieved. Energy saving effect in combination with natural lighting has been evaluated to prove that the control strategy cannot only maintain constant illumination in every working face but also significantly reduce the electric energy consumption and carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

One tourmaline-bearing leucogranite dike occurs in the Yushishanxi Nb-Ta mining area in the Yushishan district of the South Qilian orogenic belt in western China. Abundant tourmalines have been identified in the leucogranite, including disseminated, crosscutting quartz-tourmaline veins and tourmaline veinlets. Detailed petrological, geochemical, and boron isotopic studies indicate that these tourmalines have distinctive core-rim zoning signatures and significant chemical variations, which can be divided into four paragenetic generations. Generation-I tourmalines in the leucogranite have a magmatic origin and were followed by hydrothermal Generation-II, Generation-III, and Generation-IV. Tourmalines from all four generations belong to the alkali group and the schorl-dravite solid-solution series. The most notable features are the variations in Mg, Fe, and Ca contents. The variable Mg/(Mg+Fe) ratios in generations I to IV may be attributed to the multiple influx and/or interaction of initially magma-derived hydrothermal fluid with surrounding rocks, magma-derived Fe-rich hydrothermal fluid, and external metamorphic fluid. In situ B-isotope analyses of tourmaline yield a total range of -B values from -11.7 to -6.0‰. The earliest Generation-I tourmalines have -B values of -11.1 to -9.6‰, whereas Generation-II and Generation-III tourmalines record a higher -B value of -9.5 to -6.0‰ and -9.3 to -6.9‰, respectively. Such an increase is mainly controlled by boron-isotope fractionation between melt-fluid and tourmaline-fluid, Rayleigh fractionation, and also, to some extent, by a hydrothermal recharge from the same magma source. Generation-IV tourmalines have the lightest B-isotope values (down to -11.7‰). This shift back to lighter B-isotopes in the Generation-IV cannot be explained by closed-system crystallization and isotope fractionation of known phases. Alternatively, a lighter source of boron via fluid circulation from the surrounding metamorphic rocks can explain this light boron isotope composition. Therefore, we propose that an isotopically light fluid may have derived from B release during mica breakdown within the surrounding metamorphic rocks. [ABSTRACT FROM AUTHOR]

• A new Infrared beamline was constructed at HLS II. • Details of the optics and experimental techniques at the beamline. • High performance of the infrared beamline and endstations. National Synchrotron Radiation Laboratory (NSRL) owns the first dedicated synchrotron radiation facility in China, Hefei Light Source (HLS). The HLS was fully upgraded to HLS II in 2016. Following the machine upgrade, the infrared beamline was reconstructed to match the new storage ring and improved its performance. The infrared radiation is extracted from a bending magnet (1 degree port) with an acceptance angle of 65(H) × 55(V) mrad2, which including edge radiation and constant field radiaton. Two endstations were reconstructed. One is for spectroscopy experiment covering from far to near infrared, the other one is for mid-infrared microspectroscopy and imaging experiment. In this paper, we introduce the new infrared beamline and endstations in detail, including optics, experimental techniques developed at two endstations. [ABSTRACT FROM AUTHOR]

Background: Cunninghamia lanceolata (C. lanceolata) is the main fast-growing timber species in southern China. As an alternative to conventional lighting systems, LED has been demonstrated to be an artificial flexible lighting source for commercial micropropagation. The application of LED can provide rapid propagation of C. lanceolata in vitro culture. Results: We applied two-factor randomized block design to study the effects of LED photoperiods and light qualities on the growth and chlorophyll fluorescence of C. lanceolata in vitro culture plantlets. In this study, plantlets were exposed to 20 μmol·m− 2·s− 1 irradiance for three photoperiods, 8, 16, and 24 h under the three composite lights, 88.9% red+ 11.1% blue (R/B), 80.0% red+ 10.0% blue+ 10.0% purple (R/B/P), 72.7% red+ 9.1% blue+ 9.1% purple+ 9.1% green (R/B/P/G), as well as white light (12.7% red+ 3.9% blue+ 83.4% green, W) as control. The results showed that: (1) Plant height, dry weight, rooting rate, average root number, length, surface area and volume, chlorophyll, and chlorophyll fluorescence parameters were significantly affected by photoperiods, light qualities and their interactions. (2) Plantlets subjected to photoperiod 16 h had longer root, higher height, rooting rate, root number, and the higher levels of chlorophyll, chlorophyll a/b, Y (II), qP, NPQ/4 and ETRII compared to photoperiods 8 h and 24 h, while Fv/Fm during photoperiod 16 h was lower than 8 h and 24 h. Plantlets exposed to R/B/P/G generated more root and presented higher chlorophyll, Fv/Fo, Y (II), qP, and ETRII than W during photoperiods 8 and 16 h. (3) Total chlorophyll content and ETRII were significant correlated with rooting rate, root length and root volume, while Fv/Fm and ETRII were significant correlated with plant height, average root number and root surface area. (4) 16-R/B/P/G is best for growing C. lanceolata plantlets in vitro. Conclusions: This study demonstrated the effectiveness of photoperiods and light qualities using LEDs for micropropagation of C. lanceolata. The best plantlets were harvested under 16-R/B/P/G treatment. And there was a correlation between the growth and the chlorophyll and chlorophyll fluorescence of their leaves under different photoperiod and light quality. These results can contribute to improve the micropropagation process of this species. [ABSTRACT FROM AUTHOR]

Black carbon (BC), which is formed from the incomplete combustion of fuel sources (mainly fossil fuel, biofuel and open biomass burning), is a chemically inert optical absorber in the atmosphere. It has significant impacts on global climate, regional air quality and human health. During transportation, its physical and chemical characteristics as well as its sources change dramatically. To investigate the properties of BC (i.e., mass concentration, sources and optical properties) during intra-regional transport between the southern edge of the North China Plain (SE-NCP) and central China (CC), simultaneous BC observations were conducted in a megacity (Wuhan – WH) in CC, in three borderline cities (Xiangyang – XY, Suixian – SX and Hong'an – HA; from west to east) between the SE-NCP and CC, and in a city (Luohe – LH) in the SE-NCP during typical winter haze episodes. Using an Aethalometer, the highest equivalent BC (eBC) mass concentrations and the highest aerosol absorption coefficients (σabs) were found in LH in the SE-NCP, followed by the borderline cities (XY, SX and HA) and WH. The levels, sources, optical properties (i.e., σabs and absorption Ångström exponent, AAE) and geographic origins of eBC were different between clean and polluted periods. Compared with clean days, higher eBC levels (26.4 %–163 % higher) and σabs (18.2 %–236 % higher) were found during pollution episodes due to the increased combustion of fossil fuels (increased by 51.1 %–277 %), which was supported by the decreased AAE values (decreased by 7.40 %–12.7 %). The conditional bivariate probability function (CBPF) and concentration-weighted trajectory (CWT) results showed that the geographic origins of biomass burning (BC bb) and fossil fuel (BC ff) combustion-derived BC were different. Air parcels from the south dominated for border sites during clean days, with contributions of 46.0 %–58.2 %, whereas trajectories from the northeast showed higher contributions (37.5 %–51.2 %) during pollution episodes. At the SE-NCP site (LH), transboundary influences from the south (CC) exhibited a more frequent impact (with air parcels from this direction comprising 47.8 % of all parcels) on the ambient eBC levels during pollution episodes. At WH, eBC was mainly from the northeast transport route throughout the observation period. Two transportation cases showed that the mass concentrations of eBC, BC ff and σabs all increased, from upwind to downwind, whereas AAE decreased. This study highlights that intra-regional prevention and control for dominant sources at each specific site should be considered in order to improve the regional air quality. [ABSTRACT FROM AUTHOR]

Light use efficiency (LUE) is one of the important parameters on calculating terrestrial gross primary productivity (GPP) and net primary productivity (NPP). Based on 5-year (2006-2010) carbon flux and climatic variable data of a mixed plantation in north China, the seasonal and interannual variation of LUE was investigated and the biophysical controls were examined. Our results show that LUE had a distinct seasonal course, and peaked in the vigorous growing season with a value of 0.92-1.27 g C MJ. During the period of 2006-2010, annual mean LUE ranged between 0.54 and 0.62 g C MJ, and it was linearly correlated with annual GPP. In the growing season, LUE was significantly linked with the water availability variables (including monthly mean vapor pressure deficit (VPD), precipitation, evaporative fraction (EF), and the ratio of precipitation to evapotranspiration (P/ET)) and canopy conductance ( g ). However, EF was a better estimator of LUE compared with other biophysical variables. LUE decreased with an increase of the clearness index ( CI), indicating that LUE was higher under cloudy sky conditions than that under sunny sky conditions in the mixed plantation. [ABSTRACT FROM AUTHOR]

High loadings of anthropogenic carbonaceous aerosols in Chinese air influence the air quality for over one billion people and impact the regional climate. A large fraction (17-80 %) of this aerosol carbon is water-soluble, promoting cloud formation and thus climate cooling. Recent findings, however, suggest that water-soluble carbonaceous aerosols also absorb sunlight, bringing additional direct and indirect climate warming effects, yet the extent and nature of light absorption by this water-soluble "brown carbon" and its relation to sources is poorly understood. Here, we combine source estimates constrained by dual carbon isotopes with light-absorption measurements of watersoluble organic carbon (WSOC) for a March 2011 campaign at the Korea Climate Observatory at Gosan (KCOG), a receptor station in SE Yellow Sea for the outflow from northern China. The mass absorption cross section at 365 nm (MAC365) of WSOC for air masses from N. China were in general higher (0.8-1.1m2 g-1), than from other source regions (0.3-0.8m2 g-1). However, this effect corresponds to only 2-10% of the radiative forcing caused by light absorption by elemental carbon. Radiocarbon constraints show that the WSOC in Chinese outflow had significantly higher fraction fossil sources (30-50 %) compared to previous findings in S. Asia, N. America and Europe. Stable carbon (δ13C) measurements were consistent with aging during long-range air mass transport for this large fraction of carbonaceous aerosols. [ABSTRACT FROM AUTHOR]

The Shanghai Synchrotron Radiation Facility (SSRF), a 3.5 GeV storage ring based third generation light source, became open for user operations in May 2009. The performance of the SSRF complex and its user operation status in the past three years are described in this article. Brief descriptions of the experiments and achievements of some researchers at SSRF are also presented. [ABSTRACT FROM AUTHOR]

Satellite-based methods are proposed to estimate global illuminance from geostationary satellite data under local climate conditions. The data used in this model are global irradiance and global illuminance collected from the International Daylight Monitoring Programme research class station in The Chinese University of Hong Kong and the visible channel data of the Geostationary Operational Environmental Satellite 9 from May 2003 to May 2005. The proposed methods consist of an indirect method, which derives global irradiance from satellite images first and then converts global irradiance to global illuminance by a luminous efficacy model, and a direct method, which derives global illuminance directly from satellite images. The root mean squared errors of hourly global illuminance are 35% and 32% for the indirect and the direct methods, respectively. [ABSTRACT FROM AUTHOR]

Two alternative modelling approaches, physical scale modelling and numerical simulation, have been applied to the design assessment of daylight and sunlight in, and around, high-density Hong Kong housing. The ability to include both self-shading and site obstructions is crucial to this application area, which severely constrains the methods used for both approaches. While physical scale modelling could assist in estate planning, it was not feasible to study both external and internal spaces at the same model scale, even in a large, advanced facility. Due to the need to include context surroundings, physical scale models in this application would be unlikely to be able to inform design on detailed internal conditions. Numerical simulations could effectively focus on both issues and the data produced could couple to detailed modelling of other aspects, e.g. the calculation of cooling load or peak internal temperatures. Numerical modelling at this level has significant drawbacks, however, including the investment in time and expertise necessary to achieve reliable results, and the requirement for rigorous testing and validation for general acceptance of results. [ABSTRACT FROM AUTHOR]

Airborne backscatter lidar at 532 nm and in-situ measurements of black carbon (BC), carbon monoxide excess above background (ΔCO), and aerosol size distribution were carried out over Siberia in July 2013 and June 2017 in order to sample several kinds of aerosol sources. Aerosol types are derived using the Lagrangian FLEXible PARTicle dispersion model (FLEXPART) simulations and satellite observations. Six aerosol types could be identified in this work: (i) dusty aerosol mixture, (ii) Ob valley gas flaring emission, (iii) fresh forest fire, (iv) aged forest fire, (v) urban emissions over the Tomsk/Novosibirsk region (vi) long range transport of Northern China urban emission. The altitude range of aerosol layers is discussed for each aerosol type, showing transport above the boundary layer for long range transport of Northern China emissions or fresh forest fire. Comparisons of aerosol optical properties, BC and ΔCO are made between aged and fresh plumes for both the urban and forest fire emissions. An increase of aerosol optical depth at 532 nm (AOD 532 ), aerosol particle size and ΔCO is found for aged forest fire plumes. Similar results are obtained when comparing the aged urban plume from Northern China with fresh urban emissions from Siberian cities. A flight above gas flaring emissions corresponds to the largest AOD 532 and provides a possible range of 50–60 sr for the lidar ratio of these aerosol plumes often encountered in Siberia. Black carbon concentrations are relatively higher for the flaring plume (0.4–0.5 μ g. m − 3 ) than for the urban plume (0.2 μ g. m − 3 ). The largest BC concentrations are found for the fresh forest fire plume. The aerosol type identification and AOD 532 provided by CALIOP Version 4.2 data products in air masses with similar origin generally agree with the results obtained from our detailed analysis of the aerosol plume origins. [ABSTRACT FROM AUTHOR]

Two episodes with heavy air pollution in Nanjing, China, one in the summer and another one in the winter of 2017, were selected to study aerosol properties using sun photometer and ground-based measurements, together with source region analysis. The aerosol properties, the meteorological conditions, and the source regions during these two episodes were very different. The episodes were selected based on the air quality index (AQI), which reached a maximum value of 193 during the summer episode (26 May–3 June) and 304 during the winter episode (21–31 December). The particulate matter (PM) concentrations during the winter episode reached maximum values for PM2.5/10 of 254 μg m−3 and 345 μg m−3, much higher than those during the summer (73 and 185 μg m−3). In contrast, the value of aerosol optical depth (AOD) at 500 nm was higher during the summer episode (2.52 ± 0.19) than during that in the winter (1.38 ± 0.18). A high AOD value does not necessarily correspond to a high PM concentration but is also affected by factors, such as wind, Planetary Boundary Layer Height (PBLH), and relative humidity. The mean value of the Ångström Exponent (AE) varied from 0.91–1.42, suggesting that the aerosol is a mixture of invaded dust and black carbon. The absorption was stronger during the summer than during the winter, with a minimum value of the single scattering albedo (SSA) at 440 nm of 0.86 on 28 May. Low values of asymmetry factor (ASY) (0.65 at 440 nm and 0.58 at 1020 nm) suggest a large number of anthropogenic aerosols, which are absorbing fine-mode particles. The Imaginary part of the Refractive Index (IRI) was higher during the summer than during the winter, indicating there was absorbing aerosol during the summer. These differences in aerosol properties during the summer and winter episodes are discussed in terms of meteorological conditions and transport. The extreme values of PM and AOD were reached during both episodes in conditions with stable atmospheric stratification and low surface wind speed, which are conducive for the accumulation of pollutants. Potential source contribution function (PSCF) and concentration weighted trajectory (CWT) analysis show that fine mode absorbing aerosols dominate during the summer season, mainly due to emissions of local and near-by sources. In the winter, part of the air masses was arriving from arid/semi-arid regions (Shaanxi, Ningxia, Gansu, and Inner Mongolia provinces) covering long distances and transporting coarse particles to the study area, which increased the scattering characteristics of aerosols. [ABSTRACT FROM AUTHOR]