| 161. |
- Zhang, Wenxin, et al.
(författare)
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Convergence and divergence emerging in climatic controls of polynomial trends for northern ecosystem productivity over 2000–2018
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 1879-1026 .- 0048-9697.
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Tidskriftsartikel (refereegranskat)abstract
- Southwest China has been the largest terrestrial carbon sink in China over the past 30 years, but has recently experienced a succession of droughts caused by high precipitation variability, potentially threatening vegetation productivity in the region. Yet, the impact of precipitation anomalies on the vegetation primary productivity is poorly known. We used an asymmetry index (AI) to explore possible asymmetric productivity responses to precipitation anomalies in Southwest China from 2003 to 2018, using a precipitation dataset, combined with gross primary productivity (GPP), net primary productivity (NPP), and vegetation optical depth (VOD) products. Our results indicate that the vegetation primary productivity of Southwest China shows a negative asymmetry, suggesting that the increase of vegetation primary productivity during wet years exceeds the decrease during dry years. However, this negative asymmetry of vegetation primary productivity was shifted towards a positive asymmetry during the period of analysis, suggesting that the resistance of vegetation to drought, has increased with the rise in the occurrence of drought events. Among the different biomes, grassland vegetation primary productivity had the highest sensitivity to precipitation anomalies, indicating that grasslands are more flexible than other biomes and able to adjust primary productivity in response to precipitation anomalies. Furthermore, our results showed that the asymmetry of vegetation primary productivity was influenced by the effects of temperature, precipitation, solar radiation, and anthropogenic and topographic factors. These findings improve our understanding of the response of vegetation primary productivity to climate change over Southwest China.
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| 162. |
- Zhang, Xiao-Tong, et al.
(författare)
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Congenital unilateral pulmonary malformation misdiagnosed as bronchial foreign body : A review of 14 cases
- 2010
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 130:8, s. 971-976
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Tidskriftsartikel (refereegranskat)abstract
- Conclusion: Congenital unilateral pulmonary malformation can easily be misdiagnosed as a bronchial foreign body. Although rigid bronchoscopy helps the proper diagnosis, high risks associated with anesthesia and operative complications may limit its application. However, high-resolution computed tomography (CT) and three-dimensional lung reconstruction provide a non-invasive tool to improve the diagnosis of congenital unilateral pulmonary malformation. Objectives: To compare clinical manifestations, physical signs, and radiological examinations of congenital unilateral pulmonary malformation and bronchial foreign body, and summarize the characteristics and methods for diagnosis of congenital unilateral pulmonary malformation. Methods: Fourteen patients (five males and nine females, aged from 3 months to 14 years) with congenital unilateral pulmonary malformation, who were misdiagnosed or suspected as having bronchial foreign body or bronchial foreign body with pulmonary atelectasis, were analyzed retrospectively. Three typical cases are presented in detail. Results: All patients were previously misdiagnosed and treated as having pneumonia. From onset to final diagnosis, the longest misdiagnosis time was 10 years, and the shortest was 2 days. Only three patients presented with a history of foreign body inhalation. Six cases were finally diagnosed as having unilateral pulmonary malformation by rigid bronchoscope, five cases by X-ray and high-resolution CT scan, two cases by CT and three-dimensional lung reconstruction, and one case by autopsy. The malformation of left and right lungs was present in five and nine cases, respectively. Among these patients, four patients also had congenital cardiovascular diseases and other malformations, two patients underwent tracheotomy, and one patient died during salvage surgery.
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| 163. |
- Zhao-Hai, He, et al.
(författare)
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Characters of the magnetotail plasma injection surveyed from Cluster observation
- 2008
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Ingår i: Chinese Journal of Geophysics. - 0001-5733. ; 51:2, s. 307-315
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Tidskriftsartikel (refereegranskat)abstract
- The properties of proton (0 eV < E < 40 keV) in the plasma sheet are examined by means of a superposed epoch analysis, using 115 magnetotail plasma injection events which are identified from Cluster magnetotail orbit time in between 2001 and 2004. All events distribute in magnetic local time from 20 p.m. to 04 a. in. Five classes of magnetotail injection events are found to be similar with the geosynchronous observation: (1) pure ion injections; (2) ion injections followed a few minutes later by an electron injection; (3) simultaneous ion and electron injections; (4) electron injections followed a few minutes later by an ion injection; (5) pure electron injections. Proton shows a significant increase in temperature and density at the onset, and injects earthward with an increasing velocity more than the pre-injection average one. Super-posed epoch analysis on the simultaneous observation data of dusk-dawn electric field from the EFW (Electric Field and Waves) instrument, we found two different electric field configurations: ( I) electric field increases suddenly at the onset and the value is positive; (2) electric field changes the direction at the onset, and turns into a negative value. The simulation results of velocity vector after injection in equatorial plain, calculated in static magnetic (T89c) and electric (Volland-Stern) field models, agree with the statistical results mostly, and that suggests the electric drift caused by dawn-dusk convection electric field is one of the mechanisms of the particles injected earthward in magnetotail(-18 R-E < R < -10R(E)).
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| 164. |
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