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Abstract Tropospheric ozone significantly damages vegetation and reduces net primary productivity (NPP). We developed a stable linear NPP response model based on accumulated ozone exposure over a threshold of 40 parts per billion (ppb) (AOT40). We then estimated the effects of regional ozone damage on NPP for different vegetation types. The study suggests an average decrease in NPP of 24.7% due to ozone pollution in the North China Plain, similar to previous estimates ranging from 10.1% to 24.7%, with a maximum reduction exceeding 200 [g C m‐2 yr‐1] and more than 50%. Vegetation types such as broadleaf forests, needleleaf forest, crops, and grasses showed significant NPP decreases of 47.1%, 37.8%, 36.7%, and 44.6%, respectively. Declining NPP also had negative impacts on several Chinese crop species. Our work highlights the need for urgent and effective action to mitigate ozone pollution's substantial detrimental effects on ecosystem health and productivity.

To investigate the impact of aging on the sources, volatility, and viscosity of organic aerosol (OA) in Chinese outflows, a high-resolution time-of-flight aerosol mass spectrometer (HR-AMS) coupled with a thermodenuder (TD) was deployed in the spring of 2018 in Dongying, which is a regional receptor site of metropolitan emissions in the North China Plain (NCP). The average mass concentration of PM1 is 31.5±22.7 µg m−3, which is mainly composed of nitrate (33 %) and OA (25 %). The source apportionment results show that the OA is mainly contributed by oxygenated OA (OOA) from secondary sources, including background-OOA (33 %) representing a background concentration of OA (2.6 µg m−3) in the NCP area, and transported-OOA (33 %) oxidized from urban emissions. The other two factors include aged hydrocarbon-liked OA (aged-HOA, 28 %) from transported vehicle emissions and biomass burning OA (BBOA, 5 %) from local open burning. The volatility of total OA (average C*=3.2×10-4 µg m−3) in this study is generally lower than that reported in previous field studies, which is mainly due to the high OA oxidation level resulting from aging processes during transport. The volatilities of OA factors follow the order of background-OOA (average C*=2.7×10-5 µg m−3) < transported-OOA (3.7×10-4µgm-3)< aged-HOA (8.1×10-4µgm-3)< BBOA (0.012 µg m−3). Extremely low volatilities in ambient air indicate that oligomers may exist in aged plumes. The viscosity estimation suggests that the majority of ambient OA in this study behaves as semisolid (60 %), liquifies at higher relative humidity (RH) (21 %), and solidifies (19 %) during noon when the RH is low and the oxidation level is high. Finally, the estimated mixing time of molecules in 200 nm OA varies dramatically from minutes at night to years in the afternoon, emphasizing the need to consider its dynamic kinetic limits when modeling OA. In general, the overall results of this study improve our understanding of the impact of aging on OA volatility and viscosity.

The observation of Arctic sea ice is of great significance to monitoring of the polar environment, research on global climate change and application of Arctic navigation. Compared to optical imagery and SAR imagery, passive microwave images can be obtained for all-sky conditions with high time resolution. However, the spatial resolution of passive microwave images is relatively low (6.25 km – 25 km) for the observation of detailed sea ice characteristics and small-scale sea ice geographical phenomena. Therefore, in this paper, considering the suitability of different alignment and fusion strategies to the characteristics of passive microwave images of sea ice, two multi-images deep learning super-resolution (SR) algorithms, Recurrent Back-Projection Network (RBPN) and network of Temporal Group Attention (TGA), are selected to test the effects of SR technique for passive microwave images of sea ice. Both qualitative and quantitative comparisons are provided for the SR results oriented from two algorithms. Overall, the SR performance of TGA algorithm outperforms RBPN algorithm for the passive microwave images of sea ice.

Detection of subglacial lakes and interpretation their hydrological connectivity is of great importance to understanding the mass balance of Antarctic ice sheet. Over the past five decades, a large number of Radio Echo Sounding (RES) data has been collected in Antarctica. However, the identification of subglacial lakes based on RES data mainly relies on visual interpretation due to the lack of quantitative indicators for subglacial lakes distinguishing. To solve this problem, an automatic subglacial lakes detection method based on the reflective characteristics of B-scan echogram is proposed in this paper. Firstly, the echo strength of the original radar echogram is corrected for the dielectric attenuation and geometric spreading in the ice. Secondly, the original radar echogram is binarized to preserve the bright subglacial lake region, and the thickness of bright pixels is measured along the direction of A-scan. Thirdly, the thickness, the variance of the thickness in the neighbourhood and the corrected echo strength are used to obtain the response value for the subglacial lake. Finally, a threshold for the response value is determined to detect subglacial lakes. It is found that the proposed method can determine the location of the subglacial lake in Antarctica's Gamburtsev Province (AGAP) region with high accuracy.

Kisspeptin (KP) is a major positive regulator of the hypothalamo–pituitary–gonadal axis and affects female reproductive cyclicity in mammals. It offers an attractive alternative strategy to control reproduction in fixed-time artificial insemination (FTAI) protocols. We aimed to evaluate the effects of different doses of kisspeptin-10 (KP-10) on sow reproductive performance in FTAI protocols. One hundred ninety-eight weaned sows were divided into three groups at random. A FTAI–GnRH group of sows (n = 98) received 100 µg (2 mL) gonadotropin-releasing hormone (GnRH; gonadorelin) by intramuscular injection at 96 h after weaning (t = 0 h); FTAI–KPL (KPL: low-dose KP-10, n = 50), and FTAI–KPH groups of sows (KPH: high-dose KP-10, n = 50) received 0.5 or 1 mg KP-10 (2 mL) respectively at 96 h after weaning. Sows were checked twice daily for oestrus. Ultrasonographic evaluations were performed to determine the follicular diameter and time of ovulation; blood samples were collected immediately before injection (t0 = 0 min) and at 15, 30, 45, 60, 75, 90 min, 24 and 48 h postinjection. Sows were inseminated at 112 and 132 h after weaning. The oestrus rates (96 vs 92%; 96 vs 88%) and weaning-to-oestrus intervals (98.9 vs 98.6 h; 98.9 vs 97.1 h) were not affected by treatment, but oestrus in the FTAI–KPL group was significantly longer than in the FTAI–GnRH group (38.7 vs 30.0 h; P

Impacts of global climate change on the occurrence and development of air pollution have attracted more attention. This study investigates impacts of the warming Tibetan Plateau on air quality in the Sichuan Basin. Meteorological observations and ERA-Interim reanalysis data reveal that the plateau has been rapidly warming during the last 40 years (1979–2017), particularly in winter when the warming rate is approximately twice as much as the annual warming rate. Since 2013, the winter temperature over the plateau has even risen by 2 ∘C. Here we use the WRF-Chem model to lay emphasis on the impact of the 2 ∘C warming on air quality in the basin. The model results show that the 2 ∘C warming causes an enhanced easterly wind, an increase in the planetary boundary layer height (PBLH) and a decrease in the relative humidity (RH) in the basin. Enhanced easterly wind increases PM2.5 transport from the basin to the plateau. The elevated PBLH strengthens vertical diffusion of PM2.5, while the decreased RH significantly reduces secondary aerosol formation. Overall, PM2.5 concentration is reduced by 17.5 % (∼25.1 µg m−3), of which the reduction in primary and secondary aerosols is 5.4 and 19.7 µg m−3, respectively. These results reveal that the recent warming plateau has improved air quality in the basin, to a certain extent mitigating the air pollution therein. Nevertheless, the climate system is particularly complicated, and more studies are needed to demonstrate the impact of climate change on air quality in the downstream regions as the plateau is likely to continue warming. Highlights The Tibetan Plateau is rapidly warming, and the temperature has risen by 2 ∘C from 2013 to 2017. A warming plateau leads to an enhanced easterly wind, an increased PBLH and a decreased RH in the Sichuan Basin. The 2 ∘C warming significantly reduces PM2.5 concentration in the basin by 25.1 µg m−3, of which secondary aerosol is 19.7 µg m−3.

Illegal municipal solid wastes are tiny in scale and various in type, thus, it is difficult to be found by remote sensing image. To solve the problem, this paper designs and implements an illegal solid waste monitoring system based on Android App, which is composed of mobile-side and web-side. The mobile-side adopts the C/S structure, and realizes illegal solid waste location based on Gaode mobile map API on Android platform. Users can use the mobile App to report the type, scale, address and on-site photos of illegal solid waste in real time. The web-side adopts the B/S structure and develops based on the SSM framework. The web-side deploys the Tomcat server and MySQL database on the cloud server provided by Alibaba Cloud to realize the data cloud management and visual display based on Gaode Web map. The system has well-designed interfaces and convenient operations, which can effectively improve the management level and law enforcement efficiency of municipal solid waste.

Aerosol iodine isotopes are pivotal links in atmospheric circulation of iodine in both atmospheric and nuclear sciences, while their sources, temporal change and transport mechanism are still not well understood. This work presents the day-resolution temporal variation in iodine-129 (129I) and iodine-127 (127I) concentrations in aerosols from Xi'an, north-west China, during 2017/18. Both iodine isotopes have significant fluctuations with time, showing the highest levels in winter, approximately 2–3 times higher than in other seasons, but the correlation between 129I and 127I concentrations reflects that they have different sources. Aerosol 127I concentrations are found to be noticeably positively correlated with air quality index and five air pollutants. Enhanced fossil fuel combustion and inverse weather conditions can explain the increased concentrations and peaks of 127I in winter. The change in 129I concentrations confirms that the source and level of 129I in the monsoonal region were alternatively dominated by the 129I-enriched East Asian winter monsoon and the 129I-poor East Asian summer monsoon. The mean 129I∕127I number ratio of (92.7±124)×10-10 provides an atmospheric background level for the purpose of nuclear environmental safety monitoring. This study suggests that locally discharged stable127I and externally input 129I are likely involved in fine particles formation in urban air, which provides insights into the long-range transport of air pollutants and iodine's role in particulate formation in urban atmosphere.

Timed artificial insemination (TAI) is an efficient reproductive technology in batch farrowing production that aids management in pig farms. However, the effect of TAI on the reproduction performance is still controversial. This study aimed to evaluate the effects of two TAI protocols on the reproductive performance of primiparous sows. A total of 332 weaned sows were randomly allocated into three treatments. Sows assigned to Control (n = 110) were untreated and inseminated on each day in oestrus after weaning. Sows assigned to eG-TAI (n = 112) received equine chorionic gonadotropin (eCG) 24 h after weaning and gonadotropin-releasing hormone (Gonadorelin: GnRH) at oestrus, and were inseminated at 8 and 32 h later if oestrus at 0800, or 16 and 40 h later if oestrus at 1600. Sows assigned to 2e-TAI (n = 110) received eCG and GnRH 24 h and 96 h after weaning, respectively, and were inseminated 16 and 40 h after GnRH administration. Sows showing oestrus at GnRH administration or 64 h after were inseminated immediately, for a total of three inseminations. Ultrasonographic evaluations were performed to determine the follicular diameter and time of ovulation. Most sows in the 2e-TAI and eG-TAI groups ovulated 0–48 h after the GnRH injection. Our results indicated that oestrus rate within seven days after weaning in the experimental groups was higher, and weaning-to-oestrus interval was shorter than in the control group (99.3 h vs 113.5 h, P

Sulfate aerosols have profound impacts on the climate, ecosystem, visibility, and public health, but the sulfate formation pathway remains elusive. In the present study, a source-oriented WRF-Chem model is applied to simulate a persistent air pollution episode from 4 to 15 July 2015 in Beijing–Tianjin–Hebei (BTH), China, to study the contributions of four pathways to sulfate formation. When comparing simulations to measurements in BTH, the index of agreement (IOA) of meteorological parameters, air pollutants, and aerosol species generally exceeds 0.6. On average in BTH, the heterogeneous reaction of SO2 involving aerosol water and the SO2 oxidation by OH constitutes the two most important sulfate sources, with a contribution of about 35 %–38 % and 33 %–36 %, respectively. Primary sulfate emissions account for around 22 %–24 % of the total sulfate concentration. SO2 oxidation by stabilized Criegee intermediates (sCIs) also plays an appreciable role in sulfate formation, with a contribution of around 9 % when an upper limit of the reaction rate constant of sCIs with SO2 (κsCI+SO2=3.9×10-11 cm3 s−1) and a lower limit of the reaction rate constant of sCIs with H2O (κsCI+H2O=1.97×10-18 cm3 s−1) are used. Sensitivity studies reveal that there are still large uncertainties in the sulfate contribution of SO2 oxidation by sCIs. The sulfate contribution of the reaction is decreased to less than 3 % when κSCI+SO2 is decreased to 6.0×10-13 cm3 s−1. Furthermore, when κsCI+H2O is increased to 2.38×10-15 cm3 s−1 based on the reported ratio of κSCI+H2O to κSCI+SO2 (6.1×10-5), the sulfate contribution becomes insignificant at less than 2 %. Further studies need to be conducted to better determine κsCI+SO2 and κsCI+H2O to evaluate the effects of sCI chemistry on sulfate formation.

As the world's largest developing country, China has undergone ever-increasing demand for electricity during the past few decades. In 1996, China launched the Green Light Program (GLP), which became a national energy conservation activity for saving lighting electricity as well as an effective reduction of the coal consumption for power generation. Despite the great success of the GLP, its effects on haze have not been investigated and well understood. This study focused on assessing the potential coal saving induced by the improvement of luminous efficacy, the core of the GLP, and on estimating the consequent effects on the haze in the North China Plain (NCP), where a large number of power plants are located and are often engulfed by severe haze. The estimated potential coal saving induced by the GLP can reach a massive value of 120–323 million tons, accounting for 6.7 %–18.0 % of the total coal consumption for thermal power generation in China. There was a massive potential emission reduction of air pollutants from thermal power generation in the NCP, which was estimated to be 20.0–53.8 Gg for NOx and 6.9–18.7 Gg for SO2 in December 2015. The potential emission reduction induced by the GLP plays important roles in the haze formation, because the NOx and SO2 are important precursors for the formation of particles. To assess the impact of the GLP on haze, sensitivity studies were conducted by applying a regional chemical–dynamical model (WRF-CHEM). The model results suggest that in the case of lower-limit emission reduction, the PM2.5 concentration decreased by 2–5 µg m−3 in large areas of the NCP. In the case of upper-limit emission reduction, there was much more remarkable decrease in PM2.5 concentration (4–10 µg m−3). This study is a good example to illustrate that scientific innovation can induce important benefits for environment issues such as haze.

Water vapor has been proposed to amplify the severe haze pollution in China by enhancing the aerosol–radiation feedback (ARF). Observations have revealed that the near-surface PM2.5 concentrations ([PM2.5]) generally exhibit an increasing trend with relative humidity (RH) in the North China Plain (NCP) during 2015 wintertime, indicating that the aerosol liquid water (ALW) caused by hygroscopic growth could play an important role in the PM2.5 formation and accumulation. Simulations during a persistent and heavy haze pollution episode from 5 December 2015 to 4 January 2016 in the NCP were conducted using the WRF-Chem Model to comprehensively quantify contributions of the ALW effect to near-surface [PM2.5]. The WRF-Chem Model generally performs reasonably well in simulating the temporal variations in RH against measurements in the NCP. The factor separation approach (FSA) was used to evaluate the contribution of the ALW effect on the ARF, photochemistry, and heterogeneous reactions to [PM2.5]. The ALW not only augments particle sizes to enhance aerosol backward scattering but also increases the effective radius to favor aerosol forward scattering. The contribution of the ALW effect on the ARF and photochemistry to near-surface [PM2.5] is not significant, being generally within 1.0 µg m−3 on average in the NCP during the episode. Serving as an excellent substrate for heterogeneous reactions, the ALW substantially enhances the secondary aerosol (SA) formation, with an average contribution of 71 %, 10 %, 26 %, and 48 % to near-surface sulfate, nitrate, ammonium, and secondary organic aerosol concentrations. Nevertheless, the SA enhancement due to the ALW decreases the aerosol optical depth and increases the effective radius to weaken the ARF, reducing near-surface primary aerosols. The contribution of the ALW total effect to near-surface [PM2.5] is 17.5 % on average, which is overwhelmingly dominated by enhanced SA. Model sensitivities also show that when the RH is less than 80 %, the ALW progressively increases near-surface [PM2.5] but commences to decrease when the RH exceeds 80 % due to the high occurrence frequencies of precipitation.

Atmospheric aerosols scatter or absorb a fraction of the incoming solar radiation to cool or warm the atmosphere, decreasing surface temperature and altering atmospheric stability to further affect the dispersion of air pollutants in the planetary boundary layer (PBL). In the present study, simulations during a persistent and heavy haze pollution episode from 5 December 2015 to 4 January 2016 in the North China Plain (NCP) were performed using the Weather Research and Forecasting model with Chemistry (WRF-Chem) to comprehensively quantify contributions of aerosol shortwave radiative feedback (ARF) to near-surface (around 15 m above the ground surface) PM2.5 mass concentrations. The WRF-Chem model generally performs well in simulating the temporal variations and spatial distributions of air pollutants concentrations compared to observations at ambient monitoring sites in the NCP, and the simulated diurnal variations of aerosol species are also consistent with the measurements in Beijing. Additionally, the model simulates the aerosol radiative properties, the downward shortwave flux, and the PBL height against observations in the NCP well. During the episode, ARF deteriorates the haze pollution, increasing the near-surface PM2.5 concentrations in the NCP by 10.2 µg m−3 or with a contribution of 7.8 % on average. Sensitivity studies have revealed that high loadings of PM2.5 attenuate the incoming solar radiation reaching the surface to cool the low-level atmosphere, suppressing the development of the PBL, decreasing the surface wind speed, further hindering the PM2.5 dispersion, and consequently exacerbating the haze pollution in the NCP. Furthermore, when the near-surface PM2.5 mass concentration increases from around 50 to several hundred µg m−3, ARF contributes to the near-surface PM2.5 by more than 20 % during daytime in the NCP, substantially aggravating the heavy haze formation. However, when the near-surface PM2.5 concentration is less than around 50 µg m−3, ARF generally reduces the near-surface PM2.5 concentration due to the consequent perturbation of atmospheric dynamic fields.

The implementation of the Air Pollution Prevention and Control Action Plan in China since 2013 has profoundly altered the ambient pollutants in the Beijing–Tianjin–Hebei (BTH) region. Here we show observations of substantially increased O3 concentrations (about 30 %) and a remarkable increase in the ratio of organic carbon (OC) to elemental carbon (EC) in BTH during the autumn from 2013 to 2015, revealing an enhancement in atmospheric oxidizing capacity (AOC) and secondary organic aerosol (SOA) formation. To explore the impacts of increasing AOC on the SOA formation, a severe air pollution episode from 3 to 8 October 2015 with high O3 and PM2.5 concentrations is simulated using the WRF-Chem model. The model performs reasonably well in simulating the spatial distributions of PM2.5 and O3 concentrations over BTH and the temporal variations in PM2.5, O3, NO2, OC, and EC concentrations in Beijing compared to measurements. Sensitivity studies show that the change in AOC substantially influences the SOA formation in BTH. A sensitivity case characterized by a 31 % O3 decrease (or 36 % OH decrease) reduces the SOA level by about 30 % and the SOA fraction in total organic aerosol by 17 % (from 0.52 to 0.43, dimensionless). Spatially, the SOA decrease caused by reduced AOC is ubiquitous in BTH, but the spatial relationship between SOA concentrations and the AOC is dependent on the SOA precursor distribution. Studies on SOA formation pathways further show that when the AOC is reduced, the SOA from oxidation and partitioning of semivolatile primary organic aerosol (POA) and co-emitted intermediate volatile organic compounds (IVOCs) decreases remarkably, followed by those from anthropogenic and biogenic volatile organic compounds (VOCs). Meanwhile, the SOA decrease in the irreversible uptake of glyoxal and methylglyoxal on the aerosol surfaces is negligible.

Although stringent emission mitigation strategies have been carried out since 2013 in Beijing–Tianjin–Hebei (BTH), China, heavy haze with high levels of fine particulate matter (PM2.5) still frequently engulfs the region during wintertime and the nitrate contribution to PM2.5 mass has progressively increased. N2O5 heterogeneous hydrolysis is the most important pathway of nitrate formation at nighttime. In the present study, the WRF-Chem model is applied to simulate a heavy haze episode from 10 to 27 February 2014 in BTH to evaluate contributions of N2O5 heterogeneous hydrolysis to nitrate formation and effects of organic coating. The model generally performs reasonably well in simulating meteorological parameters, air pollutants, and aerosol species against observations in BTH. N2O5 heterogeneous hydrolysis with all the secondary organic aerosol assumed to be involved in coating considerably improves the nitrate simulations compared to the measurements in Beijing. On average, organic coating decreases nitrate concentrations by 8.4 % in BTH during an episode, and N2O5 heterogeneous hydrolysis with organic coating contributes about 30.1 % of nitrate concentrations. Additionally, the reaction also plays a considerable role in the heavy haze formation, with a PM2.5 contribution of about 11.6 % in BTH. Sensitivity studies also reveal that future studies need to be conducted to predict the organic aerosol hygroscopicity for accurately representing the organic coating effect on N2O5 heterogeneous hydrolysis.

Although aggressive emission control strategies have been implemented recently in the Beijing–Tianjin–Hebei area (BTH), China, pervasive and persistent haze still frequently engulfs the region during wintertime. Afforestation in BTH, primarily concentrated in the Taihang and Yan Mountains, has constituted one of the controversial factors exacerbating the haze pollution due to its slowdown of the surface wind speed. We report here an increasing trend of forest cover in BTH during 2001–2013 based on long-term satellite measurements and the impact of the afforestation on the fine-particle (PM2.5) level. Simulations using the Weather Research and Forecast model with chemistry reveal that afforestation in BTH since 2001 has generally been deteriorating the haze pollution in BTH to some degree, enhancing PM2.5 concentrations by up to 6 % on average. Complete afforestation or deforestation in the Taihang and Yan Mountains would increase or decrease the PM2.5 level within 15 % in BTH. Our model results also suggest that implementing a large ventilation corridor system would not be effective or beneficial to mitigate the haze pollution in Beijing.

In the present study, the WRF-Chem model is used to assess contributions of residential coal combustion (RCC) emissions to the air quality in Beijing–Tianjin–Hebei (BTH) during a persistent air pollution episode from 9 to 25 January 2014. In general, the predicted temporal variations and spatial distributions of the mass concentrations of air pollutants are in good agreement with observations at monitoring sites in BTH. The WRF-Chem model also reasonably reproduces the temporal variations in aerosol species when compared with the aerosol mass spectrometer measurements in Beijing. The RCC emissions play an important role in the haze formation in BTH, contributing about 23.1 % of PM2.5 (fine particulate matter) and 42.6 % of SO2 during the simulation period on average. Organic aerosols dominate the PM2.5 from the RCC emissions in BTH, with a contribution of 42.8 %, followed by sulfate (17.1 %). The air quality in Beijing is remarkably improved when the RCC emissions in BTH and the surrounding areas are excluded in model simulations, with a 30 % decrease in PM2.5 mass concentrations. However, if only the RCC emissions in Beijing are excluded, the local PM2.5 mass concentration is decreased by 18.0 % on average. Our results suggest that the implementation of the residential coal replacement by clean energy sources in Beijing is beneficial to the local air quality. Should residential coal replacement be carried out in BTH and its surrounding areas, the air quality in Beijing would be improved remarkably. Further studies would need to consider uncertainties in the emission inventory and meteorological fields.

During the Asian summer monsoon season, prevailing southeasterly–southwesterly winds are subject to delivering air pollutants from the North China Plain (NCP) to northeast and northwest China. In the present study, the WRF-CHEM model is used to evaluate contributions of trans-boundary transport of NCP emissions to the air quality in northeast and northwest China during a persistent air pollution episode from 22 to 28 May 2015. The WRF-CHEM model generally performs well in capturing the observed temporal variation and spatial distribution of fine particulate matter (PM2.5), ozone (O3), and NO2. The simulated temporal variation of aerosol species is also in good agreement with measurements in Beijing during the episode. Model simulations show that NCP emissions contribute substantially to the PM2.5 level in Liaoning and Shanxi provinces, the adjacent downwind areas of the NCP, with an average of 24.2 and 13.9 µg m−3 during the episode, respectively. The PM2.5 contributions in Jilin and Shaanxi provinces are also appreciable, with an average of 9.6 and 6.5 µg m−3, respectively. The average percentage contributions of NCP emissions to the PM2.5 level in Liaoning, Jilin, Shanxi, and Shaanxi provinces are 40.6, 27.5, 32.2, and 20.9 %, respectively. The NCP emissions contribute remarkably to the O3 level in Liaoning province, with an average of 46.5 µg m−3, varying from 23.9 to 69.5 µg m−3. The O3 level in Shanxi province is also influenced considerably by NCP emissions, with an average contribution of 35.1 µg m−3. The O3 level in Shanxi province is also influenced considerably by NCP emissions, with an average contribution of 35.1 µg m−3. The average O3 contributions of NCP emissions to Jilin and Shaanxi provinces are 28.7 and 20.7 µg m−3, respectively. The average percentage contributions of NCP emissions to the afternoon O3 level in Liaoning, Jilin, Shanxi, and Shaanxi provinces are 27.4, 19.5, 21.2, and 15.8 %, respectively. However, the effect of NCP emissions on the air quality in Inner Mongolia is generally insignificant. Therefore, effective mitigation of NCP emissions not only improves the local air quality, but is also beneficial to the air quality in northeast and northwest China during the Asian summer monsoon season.

In recent decades, the Chinese government has made a great effort in initiating large-scale ecological restoration programs (ERPs) to reduce the dust concentrations in China, especially for dust storm episodes. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover product, the ERP-induced land cover changes are quantitatively evaluated in this study. Two obvious vegetation protective barriers arise throughout China from the southwest to the northeast, which are well known as the Green Great Wall (GGW). Both the grass GGW and forest GGW are located between the dust source region (DSR) and the densely populated North China Plain (NCP). To assess the effect of ERPs on dust concentrations, a regional transport/dust model (WRF-DUST, Weather Research and Forecast model with dust) is applied to investigate the evolution of dust plumes during a strong dust storm episode from 2 to 8 March 2016. The WRF-DUST model generally performs reasonably well in reproducing the temporal variations and spatial distributions of near-surface [PMC] (mass concentration of particulate matter with aerodynamic diameter between 2.5 and 10 µm) during the dust storm event. Sensitivity experiments have indicated that the ERP-induced GGWs help to reduce the dust concentration in the NCP, especially in BTH (Beijing, Tianjin, and Hebei). When the dust storm is transported from the upwind DSR to the downwind NCP, the [PMC] reduction ranges from −5 to −15 % in the NCP, with a maximum reduction of −12.4 % (−19.2 µg m−3) in BTH and −7.6 % (−10.1 µg m−3) in the NCP. We find the dust plumes move up to the upper atmosphere and are transported from the upwind DSR to the downwind NCP, accompanied by dust decrease. During the episode, the forest GGW is nonsignificant in dust concentration control because it is of benefit for dry deposition and not for emission. Conversely, the grass GGW is beneficial in controlling dust erosion and is the dominant reason for [PMC] decrease in the NCP. Because the air pollution is severe in eastern China, especially in the NCP, and the contribution of dust episodes is significant, the reduction of dust concentrations will have important effects on severe air pollution. This study illustrates the considerable contribution of ERPs to the control of air pollution in China, especially in springtime.

The extent of polar sea ice is one of the key parameters of cryosphere and polar environmental change, which plays an important role in the study of global climate change. In this paper, the monthly product of sea ice extent, recorded from 1979 to 2016, was selected to analysis the change characteristics in multi time scales, which are annual, seasonal and monthly. It is found that the sea ice in Arctic was melting continuously for past four decades. And the melting rate was accelerated significantly since 2000. Furthermore, the Arctic was divided into thirteen sub-regions, and the change mechanism of sub-regions was discussed. Different change trends for sub-regions in four seasons were presented. Four active sub-regions were found, and the periodical analysis with the method of wavelet analysis was further carried out. The results show that the changes in the four active regions are periodic and the change period is over 10 years during the period from 1979 to 2016.

In the present study, a persistent heavy haze episode from 13 to 20 January 2014 in Beijing–Tianjin–Hebei (BTH) is simulated using the WRF-CHEM model through ensemble simulations to investigate impacts of meteorological uncertainties on the haze formation. Model results show that uncertainties in meteorological conditions substantially influence the aerosol constituent simulations at an observation site in Beijing, and the ratio of the ensemble spread to the ensemble mean (RESM) exceeds 50 %. The ensemble mean generally preforms well in reproducing the fine particles' (PM2.5) temporal variations and spatial distributions against measurements in BTH. The meteorological uncertainties do not alter the PM2.5 distribution pattern in BTH principally or dominate the haze formation and development, but remarkably affect the simulated PM2.5 level, and the RESM for the simulated PM2.5 concentrations can be up to 30 % at the regional scale. In addition, the rather large RESM in PM2.5 simulations at the city scale also causes difficulties in evaluation of the control strategies. Therefore, our results suggest that the ensemble simulation is imperative to take into account the impact of the meteorological uncertainties on the haze prediction.

Ice flow velocity is a vital parameter for estimating the ice mass balance of glaciers in Antarctica. Especially long time serial observation of the surface velocity is of great significance to assessing the relationship between Antarctic ice materials and global climate change. However, the existing research on Antarctic ice velocity based on remote sensing data since 1970s due to the harsh climate in Antarctica. This paper presents an ice flow velocity estimating method includes image pre-processing, geometric model reconstruction, image ortho-rectification and feature matching by using ARGON images token in 1963 and Landsat images collected form 1973 to 1989.Considering the temporal-spatial distributions of ARGON images and Landsat images in Antarctica, two different methods respectively based on ortho-photos pair and Non-Ortho photos are adopted in this paper. More specifically, when there exist two stereo pairs taken in different time in the glacier region, after being ortho-rectified, the stereo pairs can be used to calculate ice flow velocity based on feature matching method. Otherwise, a parallax decomposition method that separates the effect of the terrain relief from the ice flow motion is applied when there only exists one stereo pair with a certain time interval. With this method, glacier surface velocity is available in the glacier region lacked enough stereo pairs. The methods mentioned above for estimating ice flow velocity are applied in Totten, Amery and Fimbul, etc. in eastern Antarctica. Furthermore, a 1960-80s ice flow speed map in the main glaciers of East Antarctica is produced for the first time.

Rapid industrialization and urbanization have caused frequent occurrence of haze in China during wintertime in recent years. The sulfate aerosol is one of the most important components of fine particles (PM2. 5) in the atmosphere, contributing significantly to the haze formation. However, the heterogeneous formation mechanism of sulfate remains poorly characterized. The relationships of the observed sulfate with PM2. 5, iron, and relative humidity in Xi'an, China have been employed to evaluate the mechanism and to develop a parameterization of the sulfate heterogeneous formation involving aerosol water for incorporation into atmospheric chemical transport models. Model simulations with the proposed parameterization can successfully reproduce the observed sulfate rapid growth and diurnal variations in Xi'an and Beijing, China. Reasonable representation of sulfate heterogeneous formation in chemical transport models considerably improves the PM2. 5 simulations, providing the underlying basis for better understanding the haze formation and supporting the design and implementation of emission control strategies.

In the present study, the WRF-CHEM model is used to evaluate the contributions of trans-boundary transport to the air quality in Beijing during a persistent air pollution episode from 5 to 14 July 2015 in Beijing–Tianjin–Hebei (BTH), China. Generally, the predicted temporal variations and spatial distributions of PM2.5 (fine particulate matter), O3 (ozone), and NO2 are in good agreement with observations in BTH. The WRF-CHEM model also reproduces reasonably well the temporal variations of aerosol species compared to measurements in Beijing. The factor separation approach is employed to evaluate the contributions of trans-boundary transport of non-Beijing emissions to the PM2.5 and O3 levels in Beijing. On average, in the afternoon during the simulation episode, the local emissions contribute 22.4 % to the O3 level in Beijing, less than 36.6 % from non-Beijing emissions. The O3 concentrations in Beijing are decreased by 5.1 % in the afternoon due to interactions between local and non-Beijing emissions. The non-Beijing emissions play a dominant role in the PM2.5 level in Beijing, with a contribution of 61.5 %, much higher than 13.7 %, from Beijing local emissions. The emission interactions between local and non-Beijing emissions enhance the PM2.5 concentrations in Beijing, with a contribution of 5.9 %. Therefore, the air quality in Beijing is generally determined by the trans-boundary transport of non-Beijing emissions during summertime, showing that the cooperation with neighboring provinces to mitigate pollutant emissions is key for Beijing to improve air quality.

Rapid growth of industrialization, transportation, and urbanization has caused increasing emissions of ozone (O3) precursors recently, enhancing the O3 formation in eastern China. We show here that eastern China has experienced widespread and persistent O3 pollution from April to September 2015 based on the O3 observations in 223 cities. The observed maximum 1 h O3 concentrations exceed 200 µg m−3 in almost all the cities, 400 µg m−3 in more than 25 % of the cities, and even 800 µg m−3 in six cities in eastern China. The average daily maximum 1 h O3 concentrations are more than 160 µg m−3 in 45 % of the cities, and the 1 h O3 concentrations of 200 µg m−3 have been exceeded on over 10 % of days from April to September in 129 cities. Analyses of pollutant observations from 2013 to 2015 have shown that the concentrations of CO, SO2, NO2, and PM2.5 from April to September in eastern China have considerably decreased, but the O3 concentrations have increased by 9.9 %. A widespread and severe O3 pollution episode from 22 to 28 May 2015 in eastern China has been simulated using the Weather Research and Forecasting model coupled to chemistry (WRF-CHEM) to evaluate the O3 contribution of biogenic and various anthropogenic sources. The model generally performs reasonably well in simulating the temporal variations and spatial distributions of near-surface O3 concentrations. Using the factor separation approach, sensitivity studies have indicated that the industry source plays the most important role in the O3 formation and constitutes the culprit of the severe O3 pollution in eastern China. The transportation source contributes considerably to the O3 formation, and the O3 contribution of the residential source is not significant generally. The biogenic source provides a background O3 source, and also plays an important role in the south of eastern China. Further model studies are needed to comprehensively investigate O3 formation for supporting the design and implementation of O3 control strategies, considering rapid changes of emission inventories and photolysis caused by the Atmospheric Pollution Prevention and Control Action Plan released by the Chinese State Council in 2013.

With the provincial statistical data and crop field burning (CFB) activities captured by Moderate Resolution Imaging Spectroradiometer (MODIS), we extracted a detailed CFB emission inventory in the North China Plain (NCP). The WRF-CHEM model was applied to investigate the impact of CFB on air pollution during the period from 6 to 12 October 2014, corresponding to a heavy haze incident with high concentrations of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm). The WRF-CHEM model generally performed well in simulating the surface species concentrations of PM2.5, O3 and NO2 compared to the observations; in addition, it reasonably reproduced the observed temporal variations of wind speed, wind direction and planetary boundary layer height (PBLH). It was found that the CFB that occurred in southern NCP (SNCP) had a significant effect on PM2.5 concentrations locally, causing a maximum of 34 % PM2.5 increase. Under continuous southerly wind conditions, the CFB pollution plume went through a long-range transport to northern NCP (NNCP; with several mega cities, including Beijing, the capital city of China), where few CFBs occurred, resulting in a maximum of 32 % PM2.5 increase. As a result, the heavy haze in Beijing was enhanced by the CFB, which occurred in SNCP. Mountains also play significant roles in enhancing the PM2.5 pollution in NNCP through the blocking effect. The mountains blocked and redirected the airflows, causing the pollutant accumulations along the foothills of mountains. This study suggests that the prohibition of CFB should be strict not only in or around Beijing, but also on the ulterior crop growth areas of SNCP. PM2.5 emissions in SNCP should be significantly limited in order to reduce the occurrences of heavy haze events in the NNCP region.

The organic aerosol (OA) concentration is simulated in the Guanzhong Basin, China from 23 to 25 April 2013 utilizing the WRF-CHEM model. Two approaches are used to predict OA concentrations: (1) a traditional secondary organic aerosol (SOA) module; (2) a non-traditional SOA module including the volatility basis-set modeling method in which primary organic aerosol (POA) is assumed to be semivolatile and photochemically reactive. Generally, the spatial patterns and temporal variations of the calculated hourly near-surface ozone and fine particle matters agree well with the observations in Xi'an and surrounding areas. The model also yields reasonable distributions of daily PM2.5 and elemental carbon (EC) compared to the filter measurements at 29 sites in the basin. Filter-measured organic carbon (OC) and EC are used to evaluate OA, POA, and SOA using the OC ∕ EC ratio approach. Compared with the traditional SOA module, the non-traditional module significantly improves SOA simulations and explains about 88 % of the observed SOA concentration. Oxidation and partitioning of POA treated as semivolatile constitute the most important pathway for the SOA formation, contributing more than 75 % of the SOA concentrations in the basin. Residential emissions are the dominant anthropogenic OA source, constituting about 50 % of OA concentrations in urban and rural areas and 30 % in the background area. The OA contribution from transportation emissions decreases from 25 % in urban areas to 20 % in the background area, and the industry emission OA contribution is less than 6 %.

Rapid industrialization and urbanization have caused severe air pollution in the Guanzhong basin, northwestern China, with heavy haze events occurring frequently in recent winters. Using the NCEP reanalysis data, the large-scale synoptic situations influencing the Guanzhong basin during wintertime of 2013 are categorized into six types to evaluate the contribution of synoptic situations to the air pollution, including “north-low”, “southwest-trough”, “southeast-high”, “transition”, “southeast-trough”, and “inland-high”. The FLEXPART model has been utilized to demonstrate the corresponding pollutant transport patterns for the typical synoptic situations in the basin. Except for “southwest-trough” and “southeast-high” (defined as favorable synoptic situations), the other four synoptic conditions (defined as unfavorable synoptic situations) generally facilitate the accumulation of air pollutants, causing heavy air pollution in the basin. In association with the measurement of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) in the basin, the unfavorable synoptic situations correspond to high PM2.5 mass concentrations or poor air quality and vice versa. The same analysis has also been applied to winters of 2008–2012, which shows that the basin was mainly influenced by the unfavorable synoptic situations during wintertime leading to poor air quality. The WRF-CHEM model has further been applied to simulate the selected 6 days representing the typical synoptic situations during the wintertime of 2013, and the results generally show a good agreement between the modeled distributions and variations of PM2.5 and the corresponding synoptic situations, demonstrating reasonable classification for the synoptic situations in the basin. Detailed meteorological conditions, such as temperature inversion, low-level horizontal wind speed, and planetary boundary layer, all contribute to heavy air pollution events in the basin under unfavorable synoptic conditions. Considering the proportion of occurrence of unfavorable synoptic situations during wintertime, reduction of emissions is the optimum approach to mitigate the air pollution in the Guanzhong basin.

In this study, the ozone (O3) formation in China's northwest city of Xi'an and surrounding areas is investigated using the Weather Research and Forecasting atmospheric chemistry (WRF-Chem) model during the period from 22 to 24 August 2013, corresponding to a heavy air pollution episode with high concentrations of O3 and PM2.5. The model generally performs well compared to measurements in simulating the surface temperature, relative humidity, and wind speed and direction, near-surface O3 and PM2.5 mass concentrations, and aerosol constituents. High aerosol concentrations in Xi'an and surrounding areas significantly decrease the photolysis frequencies and can reduce O3 concentrations by more than 50 µg m−3 (around 25 ppb) on average. Sensitivity studies show that the O3 production regime in Xi'an and surrounding areas is complicated, varying from NOx to VOC (volatile organic compound)-sensitive chemistry. The industrial emissions contribute the most to the O3 concentrations compared to biogenic and other anthropogenic sources, but neither individual anthropogenic emission nor biogenic emission plays a dominant role in the O3 formation. Under high O3 and PM2.5 concentrations, a 50 % reduction in all the anthropogenic emissions only decreases near-surface O3 concentrations by about 14 % during daytime. The complicated O3 production regime and high aerosol levels pose a challenge for O3 control strategies in Xi'an and surrounding areas. Further investigation regarding O3 control strategies will need to be performed, taking into consideration the rapid changes in anthropogenic emissions that are not reflected in the current emission inventories and the uncertainties in the meteorological field simulations.

Black carbon (BC) aerosol at high altitudes of the Qinghai–Tibetan Plateau has potential effects on the regional climate and hydrological cycle. An intensive measurement campaign was conducted at Qinghai Lake (~ 3200 m above sea level) at the edge of the northeastern Qinghai–Tibetan Plateau during winter using a ground-based single particle soot photometer (SP2) and a photoacoustic extinctiometer (PAX). The average concentration of refractory BC (rBC) and number fraction of coated rBC were found to be 160 ± 190 ng m−3 and 59 % for the entire campaign, respectively. Significant enhancements of rBC loadings and number fraction of coated rBC were observed during a pollution episode, with an average value of 390 ng m−3 and 65 %, respectively. The mass size distribution of rBC particles showed log-normal distribution, with a peak diameter of ~ 187 nm regardless of the pollution level. Five-day backward trajectory analysis suggests that the air masses from north India contributed to the increased rBC loadings during the campaign. The potential source contribution function (PSCF) model combined with the fire counts map further proves that biomass burning from north India is an important potential source influencing the northeastern Qinghai–Tibetan Plateau during the pollution episode. The rBC mass absorption cross section (MACrBC) at λ = 532 nm was slightly larger in clean days (14.9 m2 g−1) than during the pollution episode (9.3 m2 g−1), likely due to the effects of brown carbon and the uncertainty of the MACrBC calculation. The MACrBC was positively correlated with number fraction of coated rBC during the pollution episode with an increasing rate of 0.18 (m2 g−1) %−1. The number fraction of coated rBC particles showed positive correlation with light absorption, suggesting that the increase of coated rBC particles will enhance the light absorption. Compared to rBC mass concentration, rBC mixing sate is more important in determining absorption during the pollution episode, estimated from the same percentage-wise increment of either rBC mass concentration or the number fraction of coated rBC. The estimated BC direct radiative forcing was +0.93 W m−2 for the pollution episode, which is 2 times larger than that in clean days. Our study provides insight into the potential climatic impacts of rBC aerosol transported to the Qinghai–Tibetan Plateau from south Asian regions, and is also useful for future modeling studies.

Scaled-down flume tests are largely used to support investigations for the assessment of hydrogeological risk. Achieved outcomes can be integrated to numerical analyses for the study of unstable slope collapse, debris transport, and hydrological models in general. In the set-up of such simulation platforms, a relevant role has to be given to the Spatial Sensor Network (SSN) which is in charge of collecting geo-referenced, quantitative information during experiments. Photogrammetry (including 3-D imaging sensors) can play an important role in SSN because of its capability of collecting information covering wide surfaces without any contact. The aim of this paper is to give an overview and some examples of the potential of photogrammetry in hydrogeological simulation experiments. After a general introduction on a few preliminary issues (sensors, calibration, ground reference, usage of imaging or ranging sensors), potential applications are classified into 2-D and 3-D categories. Examples are focused on a scaled-down landslide simulation platform, which has been developed at Tongji University (Shanghai, P.R. China).

Real-time indoor localization based on supporting infrastructures like wireless devices and QR codes are usually costly and labor intensive to implement. In this study, we explored a cheap alternative approach based on images for indoor localization. A user can localize him/herself by just shooting a photo of the surrounding indoor environment using the mobile phone. No any other equipment is required. This is achieved by employing image-matching and searching techniques with a dataset of pre-captured indoor images. In the beginning, a database of structured images of the indoor environment is constructed by using image matching and the bundle adjustment algorithm. Then each image’s relative pose (its position and orientation) is estimated and the semantic locations of images are tagged. A user’s location can then be determined by comparing a photo taken by the mobile phone to the database. This is done by combining quick image searching, matching and the relative orientation. This study also try to explore image acquisition plans and the processing capacity of off-the-shell mobile phones. During the whole pipeline, a collection of indoor images with both rich and poor textures are examined. Several feature detectors are used and compared. Pre-processing of complex indoor photo is also implemented on the mobile phone. The preliminary experimental results prove the feasibility of this method. In the future, we are trying to raise the efficiency of matching between indoor images and explore the fast 4G wireless communication to ensure the speed and accuracy of the localization based on a client-server framework.

An accurate estimation of a casualty rate is critical in response to earthquake disasters, and could allow an increase in the survival rate. Building damage is considered to be a major cause of earthquake casualties in developing countries. High-resolution satellite imagery (HRSI) can be used to detect the building damage in a period of a short time. This makes it possible to use a model to estimate earthquake casualties immediately after the occurrence of an earthquake. With respect to the capability of HRSI, this study built a new model for estimating the casualty rate in an earthquake disaster based on remote sensing and a geographical information system. Three groups of earthquake data, the 2003 Bam earthquake, the 2008 Wenchuan earthquake, and the 2010 Yushu earthquake, were used to evaluate this model. The results indicated that our new model significantly improved the accuracy in predicting the casualty rate. The parameters used in the model vary between developed and developing countries. This study could provide valuable information for a more efficient rescue operation in response to earthquakes.

The construction of scaled-down simulation platforms is largely used to support investigations for the assessment of hydrological risk. Achieved outcomes can be integrated and assimilated to numerical analyses for the study of unstable slope collapse, debris transport, and hydrological modeling in general. During design of such simulation platforms, a relevant role has to be given to the spatial sensor network (SSN) to deploy, which is in charge of collecting geo-referenced, quantitative information during experiments. Photogrammetry (including 3D imaging sensors) can play an important role in SSN owing to its capability of collecting 2D images and 3D point clouds data covering wide surfaces without any contact. Different kinds of metric measurements can be then extracted from datasets. The aim of this paper is to give an overview and some examples on the potential of photogrammetry in hydrogeological experiments. After a general introduction on a few preliminary issues (sensors, calibration, ground reference, usage of imaging or ranging sensors), potential applications are classified into 2D and 3D categories. Examples are focused on a scaled-down landslide simulation platform developed at Tongji University (Shanghai, P. R. China).

Hepatic progenitor cells (HPCs) are a potential cell source for liver cell transplantation but do not function like mature liver cells. We sought an effective and reliable method to induce HPC maturation. An immortalized HP14.5 albumin promoter-driven Gaussian luciferase (ALB-GLuc) cell line was established from HPCs isolated from fetal mouse liver of post coitus day 14.5 mice to investigate the effect of induction factors on ALB promoter. HP14.5 parental cells were cultured in DMEM with different combinations of 2% horse serum (HS), 0.1 µM dexamethasone (DEX), 10 ng/mL hepatic growth factor (HGF), and/or 20 ng/mL fibroblast growth factor 4 (FGF4). Trypan blue and crystal violet staining were used to assess cell proliferation with different induction conditions. Expression of hepatic markers was measured by semi-quantitative RT-PCR, Western blot, and immunofluorescence. Glycogen storage and metabolism were detected by periodic acid-Schiff and indocyanine green (ICG) staining. GLuc activity indicated ALB expression. The combination of 2% HS+0.1 µM Dex+10 ng/mL HGF+20 ng/mL FGF4 induced the highest ALB-GLuc activity. Cell proliferation decreased in 2% HS but increased by adding FGF4. Upon induction, and consistent with hepatocyte development, DLK, AFP, and CK19 expression decreased, while ALB, CK18, and UGT1A expression increased. The maturity markers tyrosine aminotransferase and apolipoprotein B were detected at days 3 and 6 post-induction, respectively. ICG uptake and glycogen synthesis were detectable at day 6 and increased over time. Therefore, we demonstrated that HPCs were induced to differentiate into functional mature hepatocytes in vitro, suggesting that factor-treated HPCs may be further explored as a means of liver cell transplantation.

Optical image is rich in spectral information, while SAR instrument can work in both day and night and obtain images through fog and clouds. Combination of these two types of complementary images shows the great advantages of better image interpretation. Image registration is an inevitable and critical problem for the applications of multi-source remote sensing images, such as image fusion, pattern recognition and change detection. However, the different characteristics between SAR and optical images, which are due to the difference in imaging mechanism and the speckle noises in SAR image, bring great challenges to the multi-source image registration. Therefore, a novel image registration algorithm based on the virtual points, derived from the corresponding region features, is proposed in this paper. Firstly, image classification methods are adopted to extract closed regions from SAR and optical images respectively. Secondly, corresponding region features are matched by constructing cost function with rotate invariant region descriptors such as area, perimeter, and the length of major and minor axes. Thirdly, virtual points derived from corresponding region features, such as the centroids, endpoints and cross points of major and minor axes, are used to calculate initial registration parameters. Finally, the parameters are corrected by an iterative calculation, which will be terminated when the overlap of corresponding region features reaches its maximum. In the experiment, WordView-2 and Radasat-2 with 0.5 m and 4.7 m spatial resolution respectively, obtained in August 2010 in Suzhou, are used to test the registration method. It is shown that the multi-source image registration algorithm presented above is effective, and the accuracy of registration is up to pixel level.

This paper describes a newly developed multi-sensor network system for landslide and hazard monitoring. Landslide hazard is one of the most destructive natural disasters, which has severely affected human safety, properties and infrastructures. We report the results of designing and deploying the multi-sensor network, based on the simulated landslide model, to monitor typical landslide areas and with a goal to predict landslide hazard and mitigate damages. The integration and deployment of the prototype sensor network were carried out in an experiment area at Tongji University in Shanghai. In order to simulate a real landslide, a contractible landslide body is constructed in the experiment area by 7m*1.5m. Then, some different kind of sensors, such as camera, GPS, crackmeter, accelerometer, laser scanning system, inclinometer, etc., are installed near or in the landslide body. After the sensors are powered, continuous sampling data will be generated. With the help of communication method, such as GPRS, and certain transport devices, such as iMesh and 3G router, all the sensor data will be transported to the server and stored in Oracle. These are the current results of an ongoing project of the center. Further research results will be updated and presented in the near future.

For high spatial resolution Remote Sensing images, it is very important to investigate the transformational methods between background and target characteristics. Only in this way rich details in images under different imaging conditions can be well extracted. Amongst the characteristics of imagery targets, texture is a visual feature that reflects the homogeneity of images and the inner attributes of different objects. What's more, it includes important information which describes the structural arrangement of objects and the connection with the surrounding environment. This paper regards texture as the major feature and investigates the transformational methods of texture feature description under different imaging conditions. This paper mainly consists of three parts:(1) Construct a wavelet filter based on Gabor wavelet, which describes texture features obtained under different imaging conditions;(2) Process and analyze the different object's texture features jointly by the relationship which is built by the wavelet description;(3) Build the transformation between the wavelet descriptions of the different object's texture features based on the characteristics of the band and direction.

Aberrant activation of β-catenin signaling has been implicated in the development of human cancers. As a Wnt signal transducer, β-catenin forms a complex with the lymphocyte enhancer-binding factor/T cell factor transcription factor and activates downstream targets that promote cell proliferation. Here we developed a Wnt-dependent β-catenin-mediated heterologous transactivation system, which consisted of a chimeric transcription factor constructed by fusing the GAL4 DNA-binding domain with the full-length β-catenin, and a GAL4-responsive reporter expressing GFP. The chimeric transcription factor was highly unstable and exerted no detectable transactivating effect on the GAL4-responsive reporter. However, lithium and Wnt1 significantly stabilized this chimeric transactivator, indicating that this transactivation system is regulated by β-catenin in a Wnt-responsive fashion. Thus, this transactivation system could be used as a functional reporter to identify potential upstream factors that deregulate β-catenin signaling during tumorigenesis, as well as to screen for potential anti-cancer agents that specifically inhibit β-catenin signaling in human tumors.