| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Svanberg, Sune, et al.
(författare)
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Laser spectroscopy applied to environmental, ecological, agricultural and food safety research
- 2017
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Ingår i: International Conference on Photonics and Imaging in Biology and Medicine, PIBM 2017. - 9781557528209 ; Part F70-PIBM 2017
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Konferensbidrag (refereegranskat)abstract
- Laser spectroscopy has a multitude of applications of importance to human and ecosystem well-being, such as in the environmental, ecological, agricultural and food safety areas. Recent work, mostly from SCNU, will be reviewed.
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| 3. |
- Zhu, Shiming, et al.
(författare)
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Insect remote sensing using a polarization sensitive cw lidar system in Chinese rice fields
- 2018
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 176
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Tidskriftsartikel (refereegranskat)abstract
- A joint Chinese-Swedish field campaign of Scheimpflug continuous-wave lidar monitoring of rice-field flying pest insects was pursued in very hot July weather conditions close to Guangzhou, China. The occurrence of insects, birds and bats with almost 200 hours of round-the-clock polarization-sensitive recordings was studied. Wing-beat frequency recordings and depolarization properties were used for target classification. Influence of weather conditions on the flying fauna was also investigated.
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| 4. |
- Song, Ziwei, et al.
(författare)
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Application of lidar remote sensing of insects in agricultural entomology on the Chinese scene
- 2020
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Ingår i: Journal of Applied Entomology. - : Wiley. - 0931-2048 .- 1439-0418. ; 144:3, s. 161-169
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Tidskriftsartikel (refereegranskat)abstract
- Insect pest management is a very important aspect for plant protection in crops production. Remote sensing provides a large number of techniques that are beneficial in entomological research. Although entomological radars have been used for studying migrations of insects for many years, most of entomological radar studies have been vertically tracing high-altitude migration behaviour of insects. Light detection and ranging (lidar) is a counterpart to radar, now operating in the optical part of the electromagnetic spectrum, which has been recently applied for monitoring of insects at low altitude. Such techniques, in particular low-cost continuous-wave (CW) bi-static systems based on the Scheimpflug arrangement, have been rapidly developing during the last decade. As a result, optical methods present new and fascinating possibilities. Based on experience from a 2-week field campaign in rice paddy fields, we here present an overview of lidar remote sensing applied to the Chinese scene. The capability of a CW Scheimpflug lidar system in monitoring the insects was studied. We present results on insect abundance in relation to time of the day and weather conditions. We also identified insect species by analysing wing-beat frequencies and studied their attraction to ultraviolet (UV) lamp located close to the horizontal laser sampling path during night time. Results showed that the insect species were abundant, that insects detected by the lidar system were attracted to light and that light rain increased the insect activity. The lidar detection system had a high read-out frequency, enabling the estimation of insect wing-beat frequencies.
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| 5. |
- Svanberg, Sune, et al.
(författare)
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Laser spectroscopy applied to environmental, ecological, food safety, and biomedical research
- 2016
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Ingår i: Optics Express. - 1094-4087. ; 24:6, s. 515-527
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Tidskriftsartikel (refereegranskat)abstract
- Laser spectroscopy provides many possibilities for multidisciplinary applications in environmental monitoring, in the ecological field, for food safety investigations, and in biomedicine. The paper gives several examples of the power of multi-disciplinary applications of laser spectroscopy as pursued in our research group. The studies utilize mostly similar and widely applicable spectroscopic approaches. Air pollution and vegetation monitoring by lidar techniques, as well as agricultural pest insect monitoring and classification by elastic scattering and fluorescence spectroscopy are described. Biomedical aspects include food safety applications and medical diagnostics of sinusitis and otitis, with strong connection to the abatement of antibiotics resistance development.
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| 6. |
- Zhu, Shiming, et al.
(författare)
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Insect abundance over Chinese rice fields in relation to environmental parameters, studied with a polarization-sensitive CW near-IR lidar system
- 2017
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Ingår i: Applied Physics B: Lasers and Optics. - : Springer Science and Business Media LLC. - 0946-2171. ; 123:7
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Tidskriftsartikel (refereegranskat)abstract
- Effective monitoring of flying insects is of major societal importance in view of the role of insects as indispensable pollinators, destructive disease vectors and economically devastating agricultural pests. The present paper reports on monitoring of flying agricultural pests using a continuous-wave lidar system in a rice-field location in Southern China. Using a Scheimpflug arrangement, range resolution over several 100 m long observational paths was achieved. The system operates with two perpendicularly polarized near-infrared lasers, which are activated intermittently, and back-scattered radiation from insects was recorded by a linear array detector placed after a linear polarizer. Our polarization sensitive system was used to monitor the flying insect diurnal activity and also the influence of changes in weather conditions, e.g., the occurrence of rain. Activity strongly peaked at dusk and rose again, although to a lower extent, just before dawn. At the onset of rainfall, a strong increase in insect counts occurred which was interpreted as the rain-induced bringing down of high-altitude migrant insects.
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| 7. |
- Duan, Zheng, et al.
(författare)
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Atmospheric mercury pollution in the xi’an area, china, studied by differential absorption lidar
- 2021
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Ingår i: Atmosphere. - : MDPI AG. - 2073-4433. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of the atmospheric concentration of polluting atomic mercury were performed using the differential absorption lidar (DIAL) technique in the Lintong district, about 35 km northeast of Xi’an, the capital of the Shaanxi province, China. Concentrations ranging from 2 to 13 ng/m3 were observed. As uniquely enabled by the lidar technique, representative average concentrations, integrated over a considerable volume, were recorded and put in relation to weather conditions, and vertical concentration profiles were measured. Considerable local non-uniformities were also observed, which may indicate the presence of localized hot-spots in the area, possibly related to ancient tombs.
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| 8. |
- Duan, Zheng, et al.
(författare)
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Optical characterization of Chinese hybrid rice using laser-induced fluorescence techniques—laboratory and remote-sensing measurements
- 2018
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Ingår i: Applied Optics. - 1559-128X. ; 57:13, s. 3481-3487
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Tidskriftsartikel (refereegranskat)abstract
- Chinese hybrid rice of different varieties, growing in paddies in the Pingqiao district, north of Xinyang city, Henan province, China, was studied in detailed spectroscopic characteristics using laser-induced fluorescence. The base for the studies was the new South China Normal University mobile lidar laboratory, which was dispatched on site, providing facilities both for laboratory studies using a 405 nm excitation source as well as remote sensing measurements at ranges from around 40 m–120 m, mostly employing the 532 nm output from a Nd:YAG laser. We, in particular, studied the spectral influence of the species varieties as well as the level of nitrogen fertilization supplied. Specially developed contrast functions as well as multivariate techniques with principal components and Fisher’s discriminate analyses were applied, and useful characterization of the rice could be achieved. The chlorophyll content mapping of the 30 zones was obtained with the remote sensing measurements.
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| 9. |
- Lian, Ming, et al.
(författare)
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Lidar mapping of atmospheric atomic mercury in the Wanshan area, China
- 2018
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 240, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- A novel mobile laser radar system was used for mapping gaseous atomic mercury (Hg0) atmospheric pollution in the Wanshan district, south of Tongren City, Guizhou Province, China. This area is heavily impacted by legacy mercury from now abandoned mining activities. Differential absorption lidar measurements were supplemented by localized point monitoring using a Lumex RA-915M Zeeman modulation mercury analyzer. Range-resolved concentration measurements in different directions were performed. Concentrations in the lower atmospheric layers often exceeded levels of 100 ng/m3 for March conditions with temperature ranging from 5 °C to 20 °C. A flux measurement of Hg0 over a vertical cross section of 0.12 km2 resulted in about 29 g/h. Vertical lidar sounding at night revealed quickly falling Hg0 concentrations with height. This is the first lidar mapping demonstration in a heavily mercury-polluted area in China, illustrating the lidar potential in complementing point monitors.
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| 10. |
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