Wyniki wyszukiwania - Biblioteka Nauki

1

Roof weakening of hydraulic fracturing for control of hanging roof in the face end of high gassy coal longwall mining: a case study

100%

Huang B. , Wang Y.

Archives of Mining Sciences

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2016

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tom Vol. 61, no. 3

601--615

EN

The occurence of hanging roof commonly arises in the face end of longwall coal mining under hard roof conditions. The sudden break and subsequent caving of a hanging roof could result in the extrusion of gas in the gob to the face, causing gas concentrations to rise sharply and to increase to over a safety-limited value. A series of linear fracturing-holes of 32 mm diameter were drilled into the roof of the entries with an anchor rig. According to the theory that the gob should be fully filled with the fragmentized falling roof rock, the drilling depth is determined as being 3~5 times the mining height if the broken expansion coefficient takes an empirical value. Considering the general extension range of cracks and the supporting form of the entryway, the spacing distance between two drilling holes is determined as being 1~2 times the crack’s range of extension. Using a mounting pipe, a high pressure resistant sealing device of a small diameter-size was sent to the designated location for the high-pressure hydraulic fracturing of the roof rock. The hydraulic fracturing created the main hydro-fracturing crack and airfoil branch cracks in the interior of the roof-rock, transforming the roof structure and weakening the strength of the roof to form a weak plane which accelerated roof caving, and eventually induced the full caving in of the roof in time with the help of ground pressure. For holes deeper than 4 m, retreating hydraulic fracturing could ensure the uniformity of crack extension. Tested and applied at several mines in Shengdong Mining District, the highest ruptured water pressure was found to be 55 MPa, and the hanging roof at the face end was reduced in length from 12 m to less than 1~2 m. This technology has eliminated the risk of the extrusion of gas which has accumulated in the gob.

PL

Stropy wiszące spotykane są powszechnie w rejonie przodka przy wybieraniu ścianowym, w warunkach dużych obciążeń stropu. Nagłe zarwanie stropu i powstały zawał mogą doprowadzić do wypływu gazu ze zrobów do strefy przodka, wskutek czego stężenia gazu gwałtownie wzrosną, przekraczając bezpieczne wartości. W stropie wywiercono serię liniowych otworów szczelinowych o średnicy 32 mm. Zgodnie z teorią, że zroby winny zostać całkowicie wypełnione rozdrobnionymi fragmentami skał ze stropu, głębokość wiercenia oblicza się jako 3-5 krotność wysokości wybierania, a wartość współczynnika rozszerzania szczelin otrzymuje się empirycznie. Uwzględniając zakres rozszerzalności szczelin i obecność obudowy chodnika, obliczono rozstęp pomiędzy kolejnymi otworami wierconymi jako 1-2 krotność zakresu rozprzestrzeniania się szczeliny. Przy pomocy rury, do wyznaczonego punktu przesłano szczeliwo odporne na wysokie ciśnienia, dla potrzeb szczelinowania hydraulicznego skał stropowych. Szczelinowanie hydrauliczne spowodowało powstanie szczeliny w skale stropowej, zmieniając tym samym strukturę stropu i powodując jego osłabienie poprzez powstanie płaszczyzny o zmniejszonej wytrzymałości, co przyspieszy zapadanie stropu, a w końcu wywoła pełny zawał, czemu sprzyjać będą także naciski powierzchniowe. W przypadku otworów o głębokości powyżej 4 m cofanie szczelinowania hydraulicznego zapewni równomierność rozprzestrzeniania się szczeliny. Metoda ta została przetestowana i zastosowana w kilku kopalniach w zagłębia Shengdond, najwyższe zastosowane ciśnienia wody wyniosły 55 MPa, zaś długość wiszącego stropu w rejonie przodka zmniejszono z 12 do poniżej 1-2 m. Zastosowanie tej technologii pozwala na wyeliminowanie ryzyka wypływu gazu nagromadzonego w wyrobisku.

2

Phaselet Algorithm Based Differential Protection for Large Generator

100%

Huang B. , Nengling T.

Przegląd Elektrotechniczny

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2013

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tom R. 89, nr 1a

243--247

EN

This paper presents a new differential protection scheme for large generator based on phaselet algorithm. The harmonic components caused by the internal fault are very important for the generator internal fault detection. With the wavelet analysis, the background noise and the high harmonic information are effectively removed. The currents are then represented to be the sampling currents, which contain important fault information. Analysis shows that the harmonic components can be enlarged after phaselet algorithm, and it also enables the efficient phasor computation of over sample windows that are not restricted to an integer multiple of a half cycle. For the severe internal fault, the criterion based on phaselet 1 and 2 have good speed performance. Simulation results demonstrate that the new scheme is successful in detecting the generator internal fault. It has higher sensitivity, and selectivity and quick speediness.

PL

W artykule opisano nową strukturę ochrony różnicowej dla dużych generatorów, opartą na algorytmie fazowym. Zastosowana analiza falkowa, pozwala na eliminację wysokich harmonicznych i szumu w tle, w pomiarach prądu. Oczyszczone próbki pomiarowe zawierają informacje dotyczące awarii, służące do ich wykrywania. Analiza wykazała, że składowe harmoniczne mogą zostać powiększone, dzięki algorytmowi fazowemu. Dodatkowo uskutecznia on obliczanie fazora w oknach próbkowania, nie ograniczonych do całkowitej wielokrotności połowy cyklu. Badania symulacyjne potwierdziły skuteczność metody, w wykrywaniu awarii wewnętrznych.

3

Alternate slicing and deposition strategies for fused deposition modelling of light curved parts

100%

Huang B. , Singamneni S.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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tom Vol. 55, nr 2

511--517

EN

Fused deposition modeling (FDM), as one of the additive manufacturing (AM) techniques, has been widely used in the manufacturing industry from the 1990s. It is relatively cheaper than other AM methods and there are other advantages such as being able to process a variety of other polymers. Currently, FDM is more likely to be suitable for direct production of the terminal-use parts, in some cases challenging traditional process such as injection molding. Research evidences indicate that change of road and layer structure would have significant influence on the meso-structure and thus impact the mechanical properties of the resulting polymer parts. Adaptive flat layer deposition and curved layer deposition have been introduced to improve the mechanical properties of terminal-use product. It is necessary that an appropriate deposition scheme is essential to ensure the best interroad and inter-layer connectivity. Uninterrupted connections are likely to result in a continuous network of polymer chains, as in the case of the conventional processes. The current research proposes conventional flat layer deposition, adaptive flat layer deposition and curved layer deposition for FDM. In particular for curved parts, curved layer deposition in expected to ensure fiber continuity and better meso-structure. Mathematical models are developed for curved slicing, practically implemented to print physical parts and test results suggest marked improvement in the mechanical characteristics of curved parts.

4

Regional distribution of non-human H7N9 avian influenza virus detections in China and construction of a predictive model

80%

Huang Z. , Li H. , Huang B.

Journal of Veterinary Research

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2021

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tom 65

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nr 3

5

Uptake and translocation of Cd and Pb in four water spinach cultivars differing in shoot Cd and Pb concentrations

80%

Huang B. , Xin J. , Liu A. , Liao K.

Polish Journal of Environmental Studies

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2012

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tom 21

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nr 5

EN

A pot experiment was conducted to study the differences of uptake and translocation of Cd and Pb in four water spinach cultivare, including two low-Cd-Pb cultivare and two high-Cd-Pb cultivars. The results showed that the characteristics of low-Cd-Pb and high-Cd-Pb accumulation were stable in the two types of cultivars, respectively. The differences in shoot Cd concentration between low-Cd-Pb and high-Cd-Pb cultivars were attributable to the differences of Cd uptake and translocation from root to shoot, but the differences of shoot Pb concentration appeared to be driven by whole-plant Pb uptake rather than by Pb translocation from root to shoot.

6

Convergence Analysis of Inverse Iterative Neural Networks with L₂ Penalty

80%

Wen Y. , Wang J. , Huang B. , Zurada J. M.

Journal of Applied Computer Science Methods

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2016

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tom Vol. 8 No. 2

85--98

EN

The iterative inversion of neural networks has been used in solving problems of adaptive control due to its good performance of information processing. In this paper an iterative inversion neural network with L₂ penalty term has been presented trained by using the classical gradient descent method. We mainly focus on the theoretical analysis of this proposed algorithm such as monotonicity of error function, boundedness of input sequences and weak (strong) convergence behavior. For bounded property of inputs, we rigorously proved that the feasible solutions of input are restricted in a measurable field. The weak convergence means that the gradient of error function with respect to input tends to zero as the iterations go to infinity while the strong convergence stands for the iterative sequence of input vectors convergence to a fixed optimal point.

7

Convergence Point of Three-strand Yarn Spinning

71%

Su X. , Gao W. , Liu X. , Xie C. , Huang B.

Fibres & Textiles in Eastern Europe

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2013

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tom Vol. 21, no. 3 (99)

48--50

EN

A theoretical model for the three-strand yarn spinning system is obtained by using the analysis method for the two-strand case presented by He et al. and setting a series of virtual intermediate variables. Then the convergence point of the three-strand yarn spinning is obtained by eliminating the intermediate variables.

PL

Opracowano teoretyczny model systemu przędzenia trójtaśmowej przędzy z wykorzystaniem modelu przędzy dwutaśmowej przedstawionego przez He i innych. Wprowadzono serię teoretycznych zmiennych przejściowych, a następnie ustalono punkt zbieżności dla systemu przędzenia przędzy trójtaśmowej przez eliminacje zmiennych pośrednich.

8

Thidiazuron enhanced somatic embryogenes is from callus lines of Arabica Coffee and subsequent plant regeneration

71%

Wang Y.-C. , Lin M.-Z. , Huang B. , Chung H.-H. , Chen J.-T.

Acta Biologica Cracoviensia. Series Botanica

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2018

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tom 60

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nr 2

9

A proteomics study of the mung bean epicotyl regulated by brassinosteroids under conditions of chilling stress

70%

Huang B. , Chu C. , Chen S. , Juan H. , Chen Y.

Cellular and Molecular Biology Letters

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2006

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tom 11

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nr 2

EN

Mung bean CYP90A2 is a putative brassinosteroid (BR) synthetic gene that shares 77% identity with the Arabidopsis CPD gene. It was strongly suppressed by chilling stress. This implies that exogenous treatment with BR could allow the plant to recover from the inhibited growth caused by chilling. In this study, we used proteomics to investigate whether the mung bean epicotyl can be regulated by brassinosteroids under conditions of chilling stress. Mung bean epicotyls whose growth was initially suppressed by chilling partly recovered their ability to elongate after treatment with 24-epibrassinolde; 17 proteins down-regulated by this chilling were re-up-regulated. These up-regulated proteins are involved in methionine assimilation, ATP synthesis, cell wall construction and the stress response. This is consistent with the re-up-regulation of methionine synthase and S-adenosyl-L-methionine synthetase, since chilling-inhibited mung bean epicotyl elongation could be partially recovered by exogenous treatment with DL-methionine. This is the first proteome established for the mung bean species. The regulatory relationship between brassinosteroids and chilling conditions was investigated, and possible mechanisms are discussed herein.

10

Modulation of virulence genes by the two-component system PhoP - PhoQ in avian pathogenic Escherichia coli

61%

Tu J. , Huang B. , Zhang Y. , Zhang Y. , Xue T. , Li S. , Qi K.

Polish Journal of Veterinary Sciences

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2016

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tom 19

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nr 1

EN

Avian pathogenic Escherichia coli (APEC) infections are a very important problem in the poultry industry. PhoP-PhoQ is a two-component system that regulates virulence genes in APEC. In this study, we constructed strains that lacked the PhoP or PhoQ genes to assess regulation of APEC pathogenicity by the PhoP-PhoQ two-component system. The PhoP mutant strain AE18, PhoQ mutant strain AE19, and PhoP/PhoQ mutant strain AE20 were constructed by the Red homologous recombination method. Swim plates were used to evaluate the motility of the APEC strains, viable bacteria counting was used to assess adhesion and invasion of chick embryo fibroblasts, and Real-Time PCR was used to measure mRNA expression of virulence genes. We first confirmed that AE18, AE19, and AE20 were successfully constructed from the wild-type AE17 strain. AE18, AE19, and AE20 showed significant decreases in motility of 70.97%, 83.87%, and 37.1%, respectively, in comparison with AE17. Moreover, in comparison with AE17, AE18, AE19, and AE20 showed significant decreases of 63.11%, 65.42%, and 30.26%, respectively, in CEF cell adhesion, and significant decreases of 59.83%, 57.82%, and 37.90%, respectively, in CEF cell invasion. In comparison with AE17, transcript levels of sodA, polA, and iss were significantly decreased in AE18, while transcript levels of fimC and iss were significantly decreased in AE19. Our results demonstrate that deletion of PhoP or PhoQ inhibits invasion and adhesion of APEC to CEF cells and significantly reduces APEC virulence by regulating transcription of virulence genes.

11

The irp2 and fyuA genes in High Pathogenicity Islands are involved in the pathogenesis of infections caused by avian pathogenic Escherichia coli (APEC)

61%

Tu J. , Hue T. , Qi K. , Shao Y. , Huang B. , Wang X. , Zhou X.

Polish Journal of Veterinary Sciences

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2016

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tom 19

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nr 1

EN

Avian pathogenic Escherichia coli (APEC) is a major bacterial infectious disease that may lead to local or systemic infections in chickens with clinical manifestations. The irp2-fyuA gene cluster has been confirmed to be the main genes involved in the synthesis of HPI. The objective of this study was to determine the influence of the irp2 and fyuA genes in the high pathogenicity island (HPI) of avian pathogenic Escherichia coli (APEC) on its pathogenicity by knocking out these genes. The ΔAE17 (lacking irp2) and ΔΔAE17 (lacking irp2 and fyuA) strains of APEC were constructed. The ΔAE17 and ΔΔAE17 strains showed significantly impaired capacity to adhere onto DF-1 cells. The LD50 results indicated that the virulence of the ΔAE17 and ΔΔAE17 strains was decreased in comparison with that of the AE17 strain. We concluded that the knock-out of the core HPI genes weakened APEC adhesion onto DF-1 cells, inhibited transcription of virulence genes, and reduced pathogenicity in chicks. The effects of genetic deletion of irp2 and fyuA on APEC were more severe than those produced by deletion of irp2 only, indicating that irp2 and fyuA co-regulate APEC pathogenicity.

12

The expression profile of Fc receptor-like Y in B lymphocytes with hepatitis B virus induced diseases

61%

Wang K. , Yang R.-L. , Pei H. , Wu H.-Y. , Zhang J. , Huang B.

Folia Histochemica et Cytobiologica

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2011

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tom 49

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nr 3

13

First report of Hepatozoon (Apicomplexa: Adeleorina) from king ratsnakes (Elaphe carinata) in Shanghai, with description of a new species

51%

Han H. , Wu Y. , Dong H. , Zhu S. , Li L. , Zhao Q. , Wu D. , Pei E. , Wang Y. , Huang B.

Acta Parasitologica

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2015

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tom 60

|

nr 2

14

IL-39 increases ROS production and promotes the phosphorylation of p38 MAPK in the apoptotic cardiomyocytes

51%

Xiong W. , Chen H. , Lu J. , Ren J. , Nie C. , Liang R. , Liu F. , Huang B. , Luo Y.

Folia Histochemica et Cytobiologica

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2021

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tom 59

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nr 3

15

Histone hyperacetylation may improve the preimplantation development and epigenetic status of cloned embryos

51%

Sun J. , Cui K. , Li Z. , Gao B. , Jiang J. , Liu Q. , Huang B. , Shi D.

Reproductive Biology

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2020

|

tom 20

|

nr 2

16

Influence of oleic acid in different solvent media on BRL 3A cell growth and viability

51%

Liu R. , Yang W. , Xia C. , Chen Y. , Gao S. , Dong Z. , Huang B. , Li R. , He P. , Xu C.

Acta Biochimica Polonica

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2018

|

tom 65

|

nr 3

17

An integrative bioinformatics analysis identified miR-375 as a candidate key regulator of malignant breast cancer

41%

Liu J. , Wang P. , Zhang P. , Du H. , Liu X. , Huang B. , Qian C. , Zhang S. , Zhu W. , Yang X. , Xiao Y. , Liu Z. , Luo D.

Journal of Applied Genetics

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2019

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tom 60

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nr 3-4