The solar disk is a bright source of multi-GeV gamma rays, due to the interactions of hadronic cosmic rays with the solar atmosphere. However, the underlying production mechanism is not understood, ...except that its efficiency must be greatly enhanced by magnetic fields that redirect some cosmic rays from ingoing to outgoing before they interact. To elucidate the nature of this emission, we perform a new analysis of solar atmospheric gamma rays with 9 years of Fermi-LAT data, which spans nearly the full 11-year solar cycle. We detect significant gamma-ray emission from the solar disk from 1 GeV up to \(\gtrsim200\) GeV. The overall gamma-ray spectrum is much harder (\(\sim E_{\gamma}^{-2.2}\)) than the cosmic-ray spectrum (\(\sim E_{\rm CR}^{-2.7}\)). We find a clear anticorrelation between the solar cycle phase and the gamma-ray flux between 1-10 GeV. Surprisingly, we observe a spectral dip between \(\sim\)30-50 GeV in an otherwise power-law spectrum. This was not predicted, is not understood, and may provide crucial clues to the gamma-ray emission mechanism. The flux above 100 GeV, which is brightest during the solar minimum, poses exciting opportunities for HAWC, LHAASO, IceCube, and KM3NeT.
The Sun is a bright source of GeV gamma rays, due to cosmic rays interacting with solar matter and photons. Key aspects of the underlying processes remain mysterious. The emission in the TeV range, ...for which there are neither observational nor theoretical studies, could provide crucial clues. The new experiments HAWC (running) and LHAASO (planned) can look at the Sun with unprecedented sensitivity. In this paper, we predict the very high-energy (up to 1000 TeV) gamma-ray flux from the solar disk and halo, due to cosmic-ray hadrons and electrons (\(e^++e^-\)), respectively. We neglect solar magnetic effects, which is valid at TeV energies; at lower energies, this gives a theoretical lower bound on the disk flux and a theoretical upper bound on the halo flux. We show that the solar-halo gamma-ray flux allows the first test of the \(\sim 5\)--70 TeV cosmic-ray electron spectrum. Further, we show that HAWC can immediately make an even stronger test with nondirectional observations of cosmic-ray electrons. Together, these gamma-ray and electron studies will provide new insights about the local density of cosmic rays and their interactions with the Sun and its magnetic environment. These studies will also be an important input to tests of new physics, including dark matter.
Traditional Chinese medicine (TCM) is a well established and time-honored practice in China, employing syndrome differentiation as a basis for the treatment of disease. According to different TCM ...syndrome typing findings, combining modern medical methods with TCM approaches can improve the quality of life and comprehensive effect on patients with nasopharyngeal carcinoma (NPC). This study investigated the relationship between TCM syndrome typing and imaging characterization to radiosensitivity as to provide objective evidence for the integration of Chinese and modern medical approaches in the treatment of NPC.
Prior to treatment, TCM syndrome typing, computed tomography (CT) and magnetic resonance imaging (MRI) were performed on 147 patients pathologically classified with NPC. The status of tumor remission was radiologically evaluated at accumulated doses of 20 Gy, 40 Gy and 60 Gy, and at 3 months after completion of radiotherapy. Statistical results were analyzed by the Friedman and K-W test procedures.
Prior to treatment, TCM syndrome typing of NPC included Lung Heat, Blood Stasis, Phlegm Congealment and Blood Stasis-Phlegm Congealment. Lung Heat typing accounted for the highest proportion at 34.7% (51/147), followed by Phlegm Congealment at 32.7% (48/147), Blood Stasis at 17.0% (25/147) and Blood Stasis-Phlegm Congealment at 15.7% (23/147). Radiological imaging demonstrated a higher incidence of cervical lymph node metastases in Phlegm Congealment and Blood Stasis-Phlegm Congealment types (P<0.05), while Blood Stasis and Blood Stasis-Phlegm Congealment types were more prone to skull base invasion (P<0.05). Residual tumor size was larger in Blood Stasis and Blood Stasis-Phlegm Congealment types than in Lung Heat and Phlegm Congealment types after 3 months of treatment (P<0.05).
Different radiological manifestations were observed in TCM syndrome typed NPC patients, with lesser radiosensitivity demonstrated in the Blood Stasis and the Blood Stasis-Phlegm Congealment types relative to the Lung Heat and Phlegm Congealment types.
Using caprolactam as a ligand, the novel title cyano-bridged yttrium(III)-ferricyanide complex, Y(caprolactam)(2)(H(2)O)(4)Fe(CN)(6) or FeY(CN)(6)(C(6)H(11)NO)(2)(H(2)O)(4), has been synthesized and ...structurally characterized. The Y atom is seven-coordinate and has approximately pentagonal-bipyramidal stereochemistry, with water molecules occupying apical positions. Of the five ligands in equatorial positions, one is the N-bound bridging cyano group, and flanking this are two O-bound caprolactam moieties, which are markedly inclined towards the bridged ferricyanide moiety such that they partially envelop it. Water molecules occupy the remaining two equatorial positions. The Y-N-C-Fe-C-N sequence of atoms lies on a crystallographic twofold axis and is therefore perfectly linear, which has not been observed previously in cyano-bridged bimetallic complexes.
The observed multi-GeV gamma-ray emission from the solar disk --- sourced by hadronic cosmic rays interacting with gas, and affected by complex magnetic fields --- is not understood. Utilizing an ...improved analysis of the Fermi-LAT data that includes the first resolved imaging of the disk, we find strong evidence that this emission is produced by two separate mechanisms. Between 2010-2017 (the rise to and fall from solar maximum), the gamma-ray emission is dominated by a polar component. Between 2008-2009 (solar minimum) this component remains present, but the total emission is instead dominated by a new equatorial component with a brighter flux and harder spectrum. Most strikingly, although 6 gamma rays above 100 GeV are observed during the 1.4 years of solar minimum, none are observed during the next 7.8 years. These features, along with a 30-50 GeV spectral dip which will be discussed in a companion paper, were not anticipated by theory. To understand the underlying physics, Fermi and HAWC observations of the imminent Cycle 25 solar minimum are crucial.
In this paper, we present an improved KNN (k-nearest neighbor) classification method called KNN+. In order to estimate its performance, we compare it with the original KNN method in the area of gene ...expression based tumor diagnosis, by the aid of two gene selection methods. The experiment results show that KNN+ is superior to KNN in general.
E-commerce pattern has been a hot research theoretically and practically. Most agricultural enterprise and their information system in Sichuan province suffer a heavy damage in earthquake. The ...reconstruction of the information system plays an important role in construction of enterprise informatization. Firstly, the atomic pattern theory is introduced and its advantages are analyzed in this paper. Secondly, by expanding the pattern of business agency network, the new e-business pattern of agricultural enterprises is presented. Finally, this paper analyzes the pattern elements, including its component, core competitive ability, the key success factors and the technical guarantees.
Nowadays, the best methods for protein secondary structure prediction are based on neural network and support vector machine, and both of them incorporate the information from multiple sequences ...alignment. However the two methods were executed on different training and testing data sets. A comparison between the two methods has been carried on here. We use the most stringent cross validation test procedure to assess the two methods on CB513, which is one of the most popular used data sets. Neural network achieved a Q/sub 3/ accuracy of 74.2%, while support vector machine got Q/sub 3/ of 76.6%, which was slightly better than NN.
3-designs with unequal set sizes called UE 3-designs are introduced to estimate all the individual brand effects and the individual competing effects in the competing effects model. It is also shown ...that an UE 3-design is universal optimal for the estimation of the individual parameters with that model. A necessary condition for the existence of UE 3-design and some properties of UE 3-designs are provided. A computer-aided approach for constructing UE 3-designs is developed and the solutions of UE 3-designs with two or three set sizes for $\upsilon \leq 10$ and $b \leq 50$ are listed whenever they exist. The construction of 3-designs using a method similar to the method of differences of constructing balanced incomplete block designs, and the extensions to UE 3-designs are discussed. Finally, the characteristics of unequal sized designs which are universal optimal for the competing effects model with one price-like attributes are stated and the construction of such designs by using orthogonal arrays of strength three is discussed.
