Research on pipeline leakage identification method based on Lyapunov exponent spectrum

In terms of resource transportation, pipelines play a very important role, however, it’s leakage is almost inevitable, so leakage monitoring has always been a research hotspot. The leakage identification of water supply pipeline is studied in this paper. The vibration caused by turbulence and cavitation at the leak point has chaotic characteristics, and the spectral distribution of which has its own special area. Chaos can be judged by the Lyapunov exponent, this means that the occurrence of the leak is judged. By this method, the leakage can be effectively identified. The above theory is verified by experiments in this paper

High Level of CXCR4 in Triple-Negative Breast Cancer Specimens Associated with a Poor Clinical Outcome

Despite high sensitivity to chemotherapy, the prognosis for triple-negative breast cancer (TNBC) remains poor because of its high rate of metastasis and low sensitivity to endocrine therapy. CXCR4 expression has been reported in many subtypes of human breast cancers, but it remains unknown whether CXCR4 is expressed in TNBC and whether CXCR4 expression in TNBC could be a prognostic indicator. TNBCs tissues were formalin fixed, paraffin embedded and hematoxylin-eosin (H&E) stained. Immunohistochemical staining was utilized to determine the CXCR4 expression in those specimens. Statistical analyses were performed using SPSS16.0 software to reveal the correlation of CXCR4 expression in TNBC specimens and cancer recurrence and cancer-related death. Our results showed that there was a strong association between CXCR4 overexpression and both menopause and the histological cancer grade of TNBC patients (p values were separately 0.004 and 0.001). The 5-y disease-free survival (DFS) and the 5-y overall survival (OS) were 57.69% and 58.33% for the low-CXCR4 group versus 42.11% and 44.74% for the high-CXCR4 group, respectively (p＝0.031 and 0.048). CXCR4 overexpression plays an important role in triple-negative breast cancers, and may be a predictor of poor prognosis

Polymorphism in Growth Hormone Gene and its Association with Growth Traits in Siniperca chuatsi

Growth hormone (GH) is a candidate gene for growth traits in fish. In this study, we assessed associations between single nucleotide polymorphisms (SNPs) in GH gene with growth traits in 357 Siniperca chuatsi individuals using high-resolution melting. Two SNPs were identified in GH gene, with one mutation in exon 5 (g.5045T>C), and one mutation in intron 5 (g.5234T>G). The corrections analysis of SNPs with the four growth traits was carried out using General Linear Model (GLM) estimation. Results showed that both of them were significantly associated with growth performance in S. chuatsi. For g.5234T>G, it was significantly associated with body weight (P＜0.01), body length (P＜0.05), body depth (P＜0.01), and body width (P＜0.01), and the individuals of genotype GG grew faster than those of genotypes TT and TG (P＜0.05). A further diplotype-trait association analysis confirmed that in fish with H3H2 (TC-GG) diplotype body weight, body length, and body width was greater than in those with other diplotypes (P＜0.05). These results demonstrated GH gene SNPs could be used as potential genetic markers in future marker assisted selection of S. chuatsi

Reaction between Azidyl Radicals and Alkynes: A Straightforward Approach to NHâ 1,2,3â Triazoles

Reaction between nitrogenâ centered radicals and unsaturated Câ C bonds is an effective synthetic strategy for the construction of nitrogenâ containing molecules. Although the reactions between nitrogenâ centered radicals and alkenes have been studied extensively, their counterpart reactions with alkynes are extremely rare. Herein, the first example of reactions between azidyl radicals and alkynes is described. This reaction initiated an efficient cascade reaction involving interâ /intramolecular radical homolytic addition toward a Câ C triple bond and a hydrogenâ atom transfer step to offer a straightforward approach to NHâ 1,2,3â triazoles under mild reaction conditions. Both the internal and terminal alkynes work well for this transformation and some heterocyclic substituents on alkynes are compatible. This mechanistically distinct strategy overcomes the inherent limitations associated with azide anion chemistry and represents a rare example of reactions between a nitrogenâ centered radicals and alkynes.Get radical! Although the reactions between nitrogenâ centered radicals and alkenes have been studied extensively, their counterpart reactions with alkynes are extremely rare. Herein, the first example of reactions between azidyl radicals and alkynes is described (see scheme).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137186/1/chem201504515.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137186/2/chem201504515-sup-0001-misc_information.pd

A new perspective on building efficient and expressive 3D equivariant graph neural networks

Geometric deep learning enables the encoding of physical symmetries in modeling 3D objects. Despite rapid progress in encoding 3D symmetries into Graph Neural Networks (GNNs), a comprehensive evaluation of the expressiveness of these networks through a local-to-global analysis lacks today. In this paper, we propose a local hierarchy of 3D isomorphism to evaluate the expressive power of equivariant GNNs and investigate the process of representing global geometric information from local patches. Our work leads to two crucial modules for designing expressive and efficient geometric GNNs; namely local substructure encoding (LSE) and frame transition encoding (FTE). To demonstrate the applicability of our theory, we propose LEFTNet which effectively implements these modules and achieves state-of-the-art performance on both scalar-valued and vector-valued molecular property prediction tasks. We further point out the design space for future developments of equivariant graph neural networks. Our codes are available at \url{https://github.com/yuanqidu/LeftNet}

Coal chemical industry membrane concentrates: characterisation and treatment by ozonation and catalytic ozonation processes

Rationale. The enactment of increasingly stringent regulations has prompted the implementation of membrane technologies such as reverse osmosis (RO) in the management of coal chemical industry (CCI) wastewaters with the goal of achieving zero liquid discharge (ZLD). However, this practice inevitably results in the production of high salinity concentrates containing refractory organic matter. Methodology. In this study, we characterised the organic composition of RO concentrates obtained from the CCI using a variety of methods including liquid chromatography– organic carbon/nitrogen detection (LC-OCND) and investigated the degradability of organic compounds present in these concentrates by ozonation and catalytic ozonation processes. Results and discussion. Organic analysis using LC-OCND revealed that humic-like substances and low molecular weight neutral compounds were the dominant constituents in the CCI concentrates examined. Measurement of degradability of the CCI concentrate by a pure ozona- tion process showed low treatment efficiency (~20% dissolved organic carbon (DOC) removal) as a result of the refractory nature of the organic compounds present in the wastewater. The degradation of these organics by a catalytic ozonation process employing a commercially available Fe-oxide based catalyst was higher than that observed by pure ozonation although the extent of organics removal (DOC removal ~47%) is still low due to the refractory nature of the organics as well as the influence of salts on the catalyst performance. Techno-economic analysis of the pure ozonation and catalytic ozonation processes indicated that the total cost of implementation of the ozonation processes (homogeneous or heterogeneous) for CCI concentrate treatment is negligible compared with the overall cost of the complete ZLD process

An efficient magnetic carbon-based solid acid treatment for corncob saccharification with high selectivity of xylose and enhanced enzymatic digestibility

An effective method for corncob saccharification was investigated over a magnetic carbon-based solid acid (MMCSA) catalyst in the aqueous phase. MMCSA was synthesized through a simple and inexpensive impregnation-carbonization-sulfonation process. Under the optimal reaction conditions (150 °C, 2 h, 0.5 g corncob, 0.5 g catalyst and 50 ml deionized water), 74.9% of xylose yield was directly obtained from corncob, with 91.7% cellulose retention in the residue. After reaction, the MMCSA was easily separated from the residue by an external magnet and reused 4 times showing high stability and catalytic activity. The enzymatic digestibility of the pretreated residue reached 95.2%, with a total sugar yield of 90.4%. The morphologic and structural properties of the natural and treated corncobs were analyzed primarily through 3D X-ray microscopy to characterize the cell wall thickness, porosity, and pore surface area distribution. The increase of macropores (pore surface areas > 200 μm2) was beneficial to the accessibility of cellulose to cellulosic enzymes, so the enzymatic digestibility was enhanced immediately. Compared with other traditional hydrolysis methods, this two-step hydrolysis approach represents an environmentally friendly and sustainable saccharification of lignocellulose to produce xylose and glucose while achieving the same level of reaction efficiency