An incremental high impedance fault detection method under non-stationary environments in distribution networks

In the non-stationary environments of distribution networks, where operating conditions continually evolve, maintaining reliable high impedance faults (HIF) detection is a significant challenge due to the frequent changes in data distribution caused by environmental variations. In this paper, we propose a novel HIF detection method based on incremental learning to handle non-stationary data stream with changing distributions. The proposed method utilizes stationary wavelet transform (SWT) to extract fault characteristics in different frequency domains from zero-sequence current data. Subsequently, a complex mapping from signal features to operational conditions is established using backpropagation neural network (BPNN) to achieve online detection of HIF. Additionally, signal features are analyzed using density-based spatial clustering of applications with noise (DBSCAN) to monitor the distribution of data. After encountering multiple distribution changes, an incremental learning process based on data replay is initiated to evolve the BPNN model for adapting to the changing data distribution. It is worth noting that the data replay mechanism ensures that the model retains previously acquired knowledge while learning from newly encountered data distributions. The proposed method was implemented in a prototype of a designed edge intelligent terminal and validated using a 10 kV testing system data. The experimental results indicate that the proposed method is capable of identifying and learning new distribution data information within non-stationary data stream. This enables the classifier model to maintain a high level of detection accuracy for the current cycle data, effectively enhancing the reliability of HIF detection

Thermal properties of MECDP copolyesters

MECDP copolyesters based on poly(ethylene terephthalate) were prepared with sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate and poly(ethylene glycol) units as modifiers. Thermal properties of these copolyesters were characterized by differential scanning calorimetry and thermal gravity analyzer. Experimental results indicated that glass transition temperature, melting temperature and thermal degradation temperature reduced with increasing the poly(ethylene glycol) content. The incorporation of poly(ethylene glycol) increased the flexibility and irregularity of molecular chains which led to lower crystallinity, and bought more ether bonds into molecular chains. Besides, the thermal degradation under oxygen condition happened easily compared to that under nitrogen condition

The MALATANG Survey : The L GAS-L IR Correlation on Sub-kiloparsec Scale in Six Nearby Star-forming Galaxies as Traced by HCN J = 4 → 3 and HCO + J = 4 → 3

This is an author-created, un-copyedited version of an article published in The Astrophysical Journal. The Version of Record is available online at https://doi.org/10.3847/1538-4357/aac512.We present HCN J = 4→3 and HCO+ J = 4→3 maps of six nearby star-forming galaxies, NGC 253, NGC 1068, IC 342, M82, M83, and NGC 6946, obtained with the James Clerk Maxwell Telescope as part of the MALATANG survey. All galaxies were mapped in the central 2×2 region at 14 (FWHM) resolution (corresponding to linear scales of ∼0.2-1.0 kpc). The LIR-Ldense relation, where the dense gas is traced by the HCN J = 4→3 and the HCO+ J = 4→3 emission, measured in our sample of spatially resolved galaxies is found to follow the linear correlation established globally in galaxies within the scatter. We find that the luminosity ratio, LIR/Ldense, shows systematic variations with LIR within individual spatially resolved galaxies, whereas the galaxy-integrated ratios vary little. A rising trend is also found between LIR/Ldense ratio and the warm-dust temperature gauged by the 70 μm/100 μm flux ratio. We find that the luminosity ratios of IR/HCN (4-3) and IR/HCO+ (4-3), which can be taken as a proxy for the star formation efficiency (SFE) in the dense molecular gas (SFE dense), appear to be nearly independent of the dense gas fraction ( f dense) for our sample of galaxies. The SFE of the total molecular gas (SFEmol) is found to increase substantially with f dense when combining our data with those on local (ultra)luminous infrared galaxies and high-z quasars. The mean LHCN(4-3) LHCO+(4-3) line ratio measured for the six targeted galaxies is 0.9±0.6. No significant correlation is found for the L'HCN(4-3) L'HCO+(4-3) ratio with the star formation rate as traced by L IR, nor with the warm-dust temperature, for the different populations of galaxies.Peer reviewe

Genome-wide identification of Cymbidium sinense WRKY gene family and the importance of its Group III members in response to abiotic stress

Transcription factors (TFs) of the WRKY family play pivotal roles in defense responses and secondary metabolism of plants. Although WRKY TFs are well documented in numerous plant species, no study has performed a genome-wide investigation of the WRKY gene family in Cymbidium sinense. In the present work, we found 64 C. sinense WRKY (CsWRKY) TFs, and they were further divided into eight subgroups. Chromosomal distribution of CsWRKYs revealed that the majority of these genes were localized on 16 chromosomes, especially on Chromosome 2. Syntenic analysis implied that 13 (20.31%) genes were derived from segmental duplication events, and 17 orthologous gene pairs were identified between Arabidopsis thaliana WRKY (AtWRKY) and CsWRKY genes. Moreover, 55 of the 64 CsWRKYs were detectable in different plant tissues in response to exposure to plant hormones. Among them, Group III members were strongly induced in response to various hormone treatments, indicating their potential essential roles in hormone signaling. We subsequently analyzed the function of CsWRKY18 in Group III. The CsWRKY18 was localized in the nucleus. The constitutive expression of CsWRKY18 in Arabidopsis led to enhanced sensitivity to ABA-mediated seed germination and root growth and elevated plant tolerance to abiotic stress within the ABA-dependent pathway. Overall, our study represented the first genome-wide characterization and functional analysis of WRKY TFs in C. sinense, which could provide useful clues about the evolution and functional description of CsWRKY genes

A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

We established a method on measuring the \dzdzb mixing parameter $y$ for BESIII experiment at the BEPCII $e^+e^-$ collider. In this method, the doubly tagged $\psi(3770) \to D^0 \overline{D^0}$ events, with one $D$ decays to CP-eigenstates and the other $D$ decays semileptonically, are used to reconstruct the signals. Since this analysis requires good $e/\pi$ separation, a likelihood approach, which combines the $dE/dx$, time of flight and the electromagnetic shower detectors information, is used for particle identification. We estimate the sensitivity of the measurement of $y$ to be 0.007 based on a $20fb^{-1}$ fully simulated MC sample.Comment: 6 pages, 7 figure

A Nation-Wide multicenter 10-year (1999-2008) retrospective clinical epidemiological study of female breast cancer in china

<p>Abstract</p> <p>Background</p> <p>According to the very limited cancer registry, incidence and mortality rates for female breast cancer in China are regarded to be increasing especially in the metropolitan areas. Representative data on the breast cancer profile of Chinese women and its time trend over years are relatively rare. The aims of the current study are to illustrate the breast cancer profile of Chinese women in time span and to explore the current treatment approaches to female breast cancer.</p> <p>Methods</p> <p>This was a hospital-based nation-wide and multi-center retrospective study of female primary breast cancer cases. China was divided into 7 regions according to the geographic distribution; from each region, one tertiary hospital was selected. With the exception of January and February, one month was randomly selected to represent each year from year 1999 to 2008 at every hospital. All inpatient cases within the selected month were reviewed and related information was collected based on the designed case report form (CRF). The Cancer Hospital/Institute, Chinese Academy of Medical Sciences (CICAMS) was the leading hospital in this study.</p> <p>Results</p> <p>Four-thousand two-hundred and eleven cases were randomly selected from the total pool of 45,200 patients and were included in the analysis. The mean age at diagnosis was 48.7 years (s.d. = 10.5 yrs) and breast cancer peaked in age group 40-49 yrs (38.6%). The most common subtype was infiltrating ductal carcinoma (86.5%). Clinical stage I & II accounted for 60.6% of 4,211 patients. Three-thousand five-hundred and thirty-four cases had estrogen receptor (ER) and progestin receptor (PR) tests, among them, 47.9% were positive for both. Two-thousand eight-hundred and forty-nine cases had human epidermal growth factor receptor 2(HER-2) tests, 25.8% of them were HER-2 positive. Among all treatment options, surgery (96.9% (4,078/4,211)) was predominant, followed by chemotherapy (81.4% (3,428/4,211). Much less patients underwent radiotherapy (22.6% (952/4,211)) and endocrine therapy (38.0% (1,599/4,211)).</p> <p>Conclusions</p> <p>The younger age of breast cancer onset among Chinese women and more advanced tumor stages pose a great challenge. Adjuvant therapy, especially radiotherapy and endocrine therapy are of great unmet needs.</p