96 research outputs found
Positron Source Simulations for ILC 1 TeV Upgrade
The generation and capture of polarized positrons at a source with a
superconducting helical undulator having 4.3 cm period and 500 GeV electron
drive beam have been simulated. The positron polarization has been calculated
for the different undulator K values (up to K = 2.5). Without applying a photon
collimator, the maximal polarization of positrons is about 25% for 231 meters
active magnet length of undulator with K = 0.7. Using an undulator with K = 2.5
and a collimator with an aperture radius of 0.9 mm results in increase of
positron polarization to 54%. The energy deposition, temperature rise and
stress induced by high intense photon beam in the rotated titanium-alloy target
have been estimated. The maximal thermal stress in the target is about 224 MPa
for the source with photon collimation to achieve a positron polarization of
54%.Comment: 8 pages, 9 figures, 1 tabl
Overestimation of thermal emittance in solenoid scans due to coupled transverse motion
The solenoid scan is a widely used method for the in-situ measurement of the
thermal emittance in a photocathode gun. The popularity of this method is due
to its simplicity and convenience since all rf photocathode guns are equipped
with an emittance compensation solenoid. This paper shows that the solenoid
scan measurement overestimates the thermal emittance in the ordinary
measurement configuration due to a weak quadrupole field (present in either the
rf gun or gun solenoid) followed by a rotation in the solenoid. This coupled
transverse dynamics aberration introduces a correlation between the beam's
horizontal and vertical motion leading to an increase in the measured 2D
transverse emittance, thus the overestimation of the thermal emittance. This
effect was systematically studied using both analytic expressions and numerical
simulations. These studies were experimentally verified using an L-band
1.6-cell rf photocathode gun with a cesium telluride cathode, which shows a
thermal emittance overestimation of 35% with a rms laser spot size of 2.7 mm.
The paper concludes by showing that the accuracy of the solenoid scan can be
improved by using a quadrupole magnet corrector, consisting of a pair of normal
and skew quadrupole magnets.Comment: 12 pages, 13 figure
Research on the Law of Garlic Price Based on Big Data
In view of the frequent fluctuation of garlic price under the market economy and the current situation of garlic price, the fluctuation of garlic price in the circulation link of garlic industry chain is analyzed, and the application mode of multidisciplinary in the agricultural industry is discussed. On the basis of the big data platform of garlic industry chain, this paper constructs a Garch model to analyze the fluctuation law of garlic price in the circulation link and provides the garlic industry service from the angle of price fluctuation combined with the economic analysis. The research shows that the average price rate of the price of garlic shows “agglomeration” and cyclical phenomenon, which has the characteristics of fragility, left and a non-normal distribution and the fitting value of the GARCH model is very close to the true value. Finally, it looks into the industrial service form from the perspective of garlic price fluctuation
A novel strategy for power sources management in connected plug-in hybrid electric vehicles based on mobile edge computation framework
This paper proposes a novel control framework and the corresponding strategy for power sources management in connected plug-in hybrid electric vehicles (cPHEVs). A mobile edge computation (MEC) based control framework is developed first, evolving the conventional on-board vehicle control unit (VCU) into the hierarchically asynchronous controller that is partly located in cloud. Elaborately contrastive analysis on the performance of processing capacity, communication frequency and communication delay manifests dramatic potential of the proposed framework in sustaining development of the cooperative control strategy for cPHEVs. On the basis of MEC based control framework, a specific cooperative strategy is constructed. The novel strategy accomplishes energy flow management between different power sources with incorporation of the active energy consumption plan and adaptive energy consumption management. The method to generate the reference battery state-of-charge (SOC) trajectories in energy consumption plan stage is emphatically investigated, fast outputting reference trajectories that are tightly close to results by global optimization methods. The estimation of distribution algorithm (EDA) is employed to output reference control policies under the specific terminal conditions assigned via the machine learning based method. Finally, simulation results highlight that the novel strategy attains superior performance in real-time application that is close to the offline global optimization solutions
ITGB5 promotes innate radiation resistance in pancreatic adenocarcinoma by promoting DNA damage repair and the MEK/ERK signaling pathway
Pancreatic adenocarcinoma (PAAD) is one of the most aggressive digestive system tumors in the world, with a low early diagnosis rate and a high mortality. Integrin beta 5 (ITGB5) is demonstrated to be a potent tumor promoter in several carcinomas. However, it is unknown whether ITGB5 participates in the occurrence and development of PAAD. In this study, we confirmed a high expression of ITGB5 in PAAD and its role in promoting invasiveness and transitivity in PAAD. Besides, the knockdown of ITGB5 increased cell sensitivity to radiation by promoting DNA damage repair and the MEK/ERK signaling pathway. Collectively, these results show that ITGB5 plays an essential role in pancreatic cancer growth and survival
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