127 research outputs found
Influence of Frost Protection Windmachine with Continuous Oscillation on Microclimate in Tea Fields
To verify the influence of frost protection windmachine with continuous oscillation on microclimate, the experimental study was conducted in a tea field in Zhenjiang, China on a typical radiation frost night. Disturbed airflow variation and protection effect were investigated. Airflow velocity of 8 points at different distance from the machine was measured during an oscillation period with an anemometer, and temperature variation of 48 points at different distance from the machine and different height above the ground was measured with temperature recorders. The changes of airflow velocity and temperature were analyzed. Where the velocity was high, the airflow-disturbed duration was as well as large. Airflow velocity at each point presented a trend of rise, fluctuation, and decline under the action of windmachine with continuous oscillation. The temperature rise with the same distance from the machine was close, among which the 10 m and 20 m away from the machine increased greatly. Disturbed airflow enlarged the temperature difference between the top and the bottom of the canopy. The windmachine with continuous oscillation is proved to be effective for tea frost protection and provides more coverage than traditional anti-frost fan with flabellate oscillation
Three-dimensional Resonance in superconducting BaFeNiAs
We use inelastic neutron scattering to study magnetic excitations of the
FeAs-based superconductor BaFeNiAs above and below its
superconducting transition temperature K. In addition to gradually
open a spin gap at the in-plane antiferromagnetic ordering wavevector
, the effect of superconductivity is to form a three dimensional
resonance with clear dispersion along the c-axis direction. The intensity of
the resonance develops like a superconducting order parameter, and the mode
occurs at distinctively different energies at and . If the
resonance energy is directly associated with the superconducting gap energy
, then is dependent on the wavevector transfers along the
c-axis. These results suggest that one must be careful in interpreting the
superconducting gap energies obtained by surface sensitive probes such as
scanning tunneling microscopy and angle resolved photoemission.Comment: 5 pages, 4 figure
Self doping effect and successive magnetic transitions in superconducting SrVFeAsO
We have studied a quinary Fe-based superconductor SrVFeAsO by the
measurements of x-ray diffraction, x-ray absorption, M\"{o}ssbauer spectrum,
resistivity, magnetization and specific heat. This apparently undoped
oxyarsenide is shown to be self doped via electron transfer from the V
ions. We observed successive magnetic transitions within the VO layers: an
antiferromagnetic transition at 150 K followed by a weak ferromagnetic
transition at 55 K. The spin orderings within the VO planes are discussed
based on mixed valence of V and V.Comment: One Table and more references are adde
Quantitative Research of 11C-CFT and 18F-FDG PET in Parkinson’s Disease: A Pilot Study With NeuroQ Software
Dopamine transporter (DAT) and glucose metabolism imaging have been applied in the diagnosis of Parkinson’s disease (PD). We explored the possibility of evaluating for PD with NeuroQ software by analyzing 11C-2β-carbomethoxy-3β-(4-fluorophenyl) tropane (11C-CFT) and 18F-FDG PET/CT. We retrospectively analyzed brain 11C-CFT and 18F-FDG PET/CT of 38 patients with parkinsonism, including 20 with PD, 10 with multiple system atrophy (MSA) and 8 with essential tremor (ET), and compared them with the PET/CT of 11 normal healthy controls (NC). PD patients were divided into mild and moderate-severe grade according to the Hoehn-Yahr (H&Y) scale. The 11C-CFT uptake in the caudate nuclei (CN) and putamen (Pu) normalized with cerebellum (CN/Cb and Pu/Cb) were obtained with a manual method and NeuroQ software, and their diagnostic performance was compared.18F-FDG uptake of specific regions was also obtained with NeuroQ, and the enhancement effect for the differential diagnosis was evaluated. There was significant agreement between the manual method and the NeuroQ method for 11C-CFT uptake by CN (r2= 0.680) and Pu (r2= 0.770). 11C-CFT uptake by CN and Pu in PD and MSA patients was significantly lower compared to NC and ET patients. The cutoffs of CN/Cb and Pu/Cb for the distinction between PD and NC were 1.71 and 2.20, respectively. No difference in uptake ratios occurred between PD and MSA. 18F-FDG uptake by the pons and cerebellum in the MSA group was markedly decreased. It was highly accurate in distinguishing between PD and MSA when combined with analysis of 11C-CFT uptake. Pu/Cb decreased significantly in mild grade PD compared to NC group (1.92 ± 0.33 vs. 2.82 ± 0.43); however no statistically significant decrease in CN/Cb was observed until moderate-severe grade PD (1.43 ± 0.11 vs. 2.23 ± 0.36). In early asymmetric PD, a statistically significant difference could be seen with Pu/Cb between the symptomatic and asymptomatic side (2.17 ± 0.30 vs. 1.95 ± 0.22). 11C-CFT and 18F-FDG PET/CT can be analyzed quantitatively with NeuroQ software, which provides an accurate method for the diagnosis and severity evaluation of PD
Cluster-randomized controlled trial of the effects of free glasses on purchase of children's glasses in China:The PRICE (Potentiating Rural Investment in Children's Eyecare) study
Offering free glasses can be important to increase children's wear. We sought to assess whether "Upgrade glasses" could avoid reduced glasses sales when offering free glasses to children in China.In this cluster-randomized, controlled trial, children with uncorrected visual acuity (VA)6/12 in both eyes at 138 randomly-selected primary schools in 9 counties in Guangdong and Yunnan provinces, China, were randomized by school to one of four groups: glasses prescription only (Control); Free Glasses; Free Glasses + offer of 30 Upgrade Glasses. Spectacle purchase (main outcome) was assessed 6 months after randomization.Among 10,234 children screened, 882 (8.62%, mean age 10.6 years, 45.5% boys) were eligible and randomized: 257 (29.1%) at 37 schools to Control; 253 (28.7%) at 32 schools to Free Glasses; 187 (21.2%) at 31 schools to Free Glasses + 30 Upgrade. Baseline ownership among these children needing glasses was 11.8% (104/882), and 867 (98.3%) children completed follow-up. Glasses purchase was significantly less likely when free glasses were given: Control: 59/250 = 23.6%; Free glasses: 32/252 = 12.7%, P = 0.010. Offering Upgrade Glasses eliminated this difference: Free + 30 Upgrade: 38/182 = 20.9%, RR 0.91 (0.59, 1.42), P = 0.69.Upgrade glasses can prevent reductions in glasses purchase when free spectacles are provided, providing important program income.ClinicalTrials.gov Identifier: NCT02231606. Registered on 31 August 2014
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Erratum: Sequence data and association statistics from 12,940 type 2 diabetes cases and controls.
This corrects the article DOI: 10.1038/sdata.2017.179
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