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1

Replacing RQD and discontinuity spacing with the modified blockiness index in the Rock Mass Rating system

Chen Q., Yin T., Niu W.

Archives of Mining Sciences

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2018

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Vol. 63, no. 2

353--382

EN

The evaluation accuracies of rock mass structures based on the ratings of the Rock Quality Designation (RQD) and discontinuity spacing (S) in the Rock Mass Rating (RMR) system are very limited due to the inherent restrictions of RQD and S. This study presents an improvement that replaces these two parameters with the modified blockiness index (Bz) in the RMR system. Before proceeding with this replacement, it is necessary for theoretical model building to make an assumption that the discontinuity network contains three sets of mutually orthogonal disc-shaped discontinuities with the same diameter and spacing of discontinuities. Then, a total of 35 types of theoretical DFN (Discrete Fracture Network) models possessing the different structures were built based on the International Society for Rock Mechanics (ISRM) discontinuity classification (ISRM, 1978). In addition, the RQD values of each model were measured by setting the scanlines in the models, and the Bz values were computed following the modified blockiness evaluation method. Correlations between the three indices (i.e., Bz, RQD and S) were explored, and the reliability of the substitution was subsequently verified. Finally, RMR systems based on the proposed method and the standard approach were applied to real cases, and comparisons between the two methods were performed. This study reveals that RQD is well correlated with S but is difficult to relate to the discontinuity diameter (D), and Bz has a good correlation with RQD/S. Additionally, the ratings of RQD and S are always far from the actual rock mass structure, and the Bz ratings are found to give better characterizations of rock mass structures. This substitution in the RMR system was found to be acceptable and practical.

PL

Dokładność oceny struktury górotworu w oparciu o określenie jakości skał oraz odległości pomiędzy kolejnymi nieciągłościami (S) w systemie oceny stanu górotworu (RMR-Rock Mass Rating) jest mocno ograniczona z powodu ograniczeń wbudowanych w samą strukturę modelu RQD i w procedury obliczania odległości pomiędzy nieciągłościami. W niniejszej pracy zaproponowano ulepszone rozwiązanie zakładające zastąpienie powyższych dwóch parametrów przez jeden wskaźnik oceny struktury blokowej (Bz) w systemie RMR. Jednakże przed zastąpieniem wskaźników konieczne okazało się opracowanie modelu teoretycznego opartego na założeniu że sieć nieciągłości zawiera trzy zbiory wzajemnie ortogonalnych nieciągłości w kształcie dysków, mających tę samą średnicę i zlokalizowanych w równych odstępach. Następnie opracowano w sumie 35 typów teoretycznych dyskretnych modeli nieciągłości DFN (Discrete Fracture Network) o różnych strukturach w oparciu o klasyfikację nieciągłości określoną przez International Society for Rock Mechanics (ISRM, 1978). Ponadto, wartości RQD dla każdego z modeli zostały zmierzone poprzez odpowiednie ustawienie linii wybierania w modelu, zaś wartości Bz obliczono w oparciu o zmodyfikowaną metodę oceny struktury blokowej. Badano wzajemne korelacje pomiędzy trzema wskaźnikami (Bz, RQD, S), badano także wiarygodność modeli po podstawieniu. W etapie końcowym, system RMR oparty na zaproponowanej metodzie i podejściu standardowym został zastosowany do analizy rzeczywistych przypadków w celu porównania wyników uzyskanych w oparciu o powyższe dwie metody. Wyniki wskazały wysoki stopień korelacji wielkości RQD i S, choć trudno znaleźć korelacje pomiędzy RQD a średnicą nieciągłości (D). Stwierdzono także wysoki stopień korelacji pomiędzy wartościami RQD i S. Ponadto, stwierdzono że wielkości RQD i S nie opisują dokładnie rzeczywistej struktury górotworu, zaś ocena oparta na wskaźniku Bz wydaje się lepiej charakteryzować jego strukturę. Podstawienie tego parametru do systemu klasyfikacji RMR wydaje się więc akceptowalne i uzasadnione praktycznie.

2

Design and implementation of large vessel navigation system based on beidou cors

Huang P., Liu Y., Du Z., Chen Q., Chen J.

Polish Maritime Research

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2017

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S 3

12--15

EN

The ship’s pilot can obtain the ship auxiliary information through the navigation system, when berthing system can display the parameters such as traverse speed and distance of the ship. But most of the system data show that there are insufficient precision. Taking the CORS system to obtain the location information, data Calculation of Berthing System based on Polar Coordinate Algorithm, this paper puts forward a solution to the “dead point” of the berthing and aiding system, which has a certain reference value for the design of the ship berthing assistance system.

3

Theoretical investigation of vanadium oxide film with surface microstructure

Hong W., Wang Z., Chen Q., Sheng C., Gu G., Luo P., Xie Y.

Optica Applicata

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2017

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Vol. 47, nr 4

601--609

EN

This paper presents a method to design a surface microstructure of vanadium oxide to enhance optical absorption. This method, using a density of eigenfrequency, can be calculated by a planar wave expand method, to indicate the absorption efficiency of a dispersion material, which can be used as an approach method for further design. Based on this, a nanostructure-based vanadium oxide film is designed and simulated to validate this method. The simulation results show that the tendency of density of eigenfrequency is corresponding to the tendency of optical absorption enhancement. Moreover, this structure can achieve high optical broadband absorption when the material dispersion is considered. High optical absorption enhancement can be achieved by adjusting the geometrical parameters; our maximum overall enhancement absorption ratio was 31.84% at the metal phase, which can be attributed to the enhancement effect of a photonic band edge.

4

Effects of vinasse and silica mud on the performance of thermophilic fermentation of brewery sludge from brewery waste substrates

Xin Y., Shen J., Wang B., Zhu X., Wang Y., Wang G., Chen Q.

Environment Protection Engineering

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2017

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Vol. 43, nr 2

119--127

EN

The anaerobic digestion of mixing brewery sludge with vinasse and silica mud at various ratios under thermophilic conditions was explored. Vinasse, silica mud and beer sludge (the sludge from the treatment of beer wastewater) are the main solid wastes of the beer production. Uncontrolled decom-position of these wastes could cause large-scale contamination of soil, water, and air. The results of the investigation showed that the optimal ratio of beer sludge and vinasse was 1:1 under total solids of 10%, producing the highest amount of gas of 1.34 cm3/g within 24 h and 4.06 cm3/g in 10 days. The silica mud weakened the fermentation process and reduced the gas production, and the concentration of total organic carbon, total nitrogen and volatile solids decreased during the digestion. For the mixture of brewery sludge and vinasse, the content of the total organic matter in the biogas manure was more than 60% and the value of pH was 6.5 after the anaerobic digestion, indicating that the manure can be used as an organic fertilizer.

5

The Effect of Knitting Parameter and Finishing on Elastic Property of PET/PBT Warp Knitted Fabric

Chen Q., Ma P., Mao H., Miao X., Jiang G.

Autex Research Journal

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2017

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Vol. 17, no. 4

250--260

EN

This study investigated the elastic elongation and elastic recovery of the elastic warp knittedfabric made of PET (polyethylene terephthalate) and PBT (polybutylene terephthalate) filament. Using 50/24F PET and 50D/24F PBT in two threadingbars, the tricot, locknit and satin warp knitted fabrics were produced on the E28 tricot warpknitting machine. The knitting parameters influencing the elastic elongation under 100N wereanalyzed in terms of fabric structure, yarn run-in speed and drawing density set on machine.Besides, dyeing temperature and heat setting temperature/time were also examined in order toretain proper elastic elongation and elastic recovery. The relationship between elastic elongationand knitting parameter and finishing parameter were analyzed. Finally, the elastic recovery of PET/PBT warp knitted fabric was examined to demonstrate the elastic property of final finishedfabric. This study could help us to further exploit the use of PET/PBT warp knitted fabric in thedevelopment of elastic garment in future.

6

The Comfort Properties of Two Differential-Shrinkage Polyester Warp Knitted Fabrics

Chen Q., Miao X., Mao H., Ma P., Jiang G.

Autex Research Journal

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2016

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Vol. 16, no. 2

90--99

EN

Single-layered warp knitted fabrics were produced by the 60D/36F (containing 36 filaments) polyester yarn with differential shrinkage (DS) property in this study. Due to the differential shrinkage property, the fabric becomes curly and bulkier, simulating cotton fabric in terms of its appearance and fabric handle. The performance and appearance of these DS polyester warp knitted fabrics were evaluated objectively and subjectively. The testing results demonstrated that the DS polyester warp knitted fabric had better abrasion property, worse pilling resistance due to the mechanical property of polyester yarn when compared with 100% cotton warp knitted fabric. Meanwhile, lower water vapour permeability and air resistance were found for DS polyester warp knitted fabric resulting from the dense structure of yarn shrinkage after heat-moisture treatment. Besides, the fabric handle was evaluated by Kawabata evaluation system and subject to trial under dry and wet fabric condition. DS polyester warp knitted fabrics provide better recovery under low stress mechanical pressure. The subjective evaluation result shows that the warp knitted fabrics made of DS polyester had similar handle against cotton warp knitted fabric in terms of prickle, smooth, comfort and dry feeling in both dry and wet testing conditions.

7

Comprehensive characterization and quantification of phillyrin in the fruits of Forsythia suspensa and its medicinal preparations by liquid chromatography-ion trap mass spectrometry

Chen J., Chen Q., Yu F., Huang H., Li P., Zhu J., He X.

Acta Chromatographica

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2016

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Vol. 28, no. 1

145--157

EN

A rapid and sensitive method for the identification and quantification of phillyrin (POG) in Forsythia suspense is described. The phillyrin standard solution was directly infused into the ion trap mass spectrometers (IT-MS) for collecting the MSn spectra. The electrospray ionization (ESI) mass spectral fragmentation pathway of phillyrin was proposed, and the ESI-MSn fragmentation behavior of phillyrin was deduced in detail. The major product ion at m/z 355 belongs to furofuran, which was formed by loss the glucopyranoside (180 Da), and the characteristic fragment ions m/z 473, 395, 337, 309, and 249 were observed. The loss of 18 Da could arise from two different fragmentation pathways, and the observed ion was composed of a mixture of two different structural ions. Quantification of phillyrin was assigned in positive-ion mode at a product ion at m/z 557 → 355 by liquid chromatography-mass spectrometry (LC-MS). The LC-MS method was validated for linearity, sensitivity, accuracy, and precision and then used to determine the content of the phillyrin. Lastly, the LC-MS method was successfully applied to determine phillyrin in real sample F. suspense and three of its medicinal preparations in the positive mode at the first time.

8

Environmental Regulations and Industrial Performance Evidence from the Revision of Water Pollution Prevention and Control Law in China

Yu W., Chen Q.

Problemy Ekorozwoju

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2015

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Vol. 10, nr 1

41--48

EN

Stringent environmental regulations are urgently needed as China’s environmental pollution is increasingly become an important issue both domestically and internationally. Based on a natural experiment of water pollution prevention and Control Law’s revision in 2008(WPPCL2008), this study investigates the effects of environmental regulatory policy on industry in China by using the industrial sectors’ data from 2003-2011. The results show that the WPPCL2008 significantly increases the total labor productivity, but has no ROA-inducement effect for water pollution-intensive sectors. Furthermore, WPPCL2008 has an insignificant negative influence on employment level of the water pollution-intensive sectors. At the same time, this study provides evidence on the effectiveness of the current written environmental laws in China.

PL

Tworzenie rygorystycznego systemu prawa środowiskowego jest w Chinach niezbędne, z uwagi na rosnący poziom zanieczyszczenia środowiska i to tak w wymiarze krajowym, jak i międzynarodowym. Artykuł jako przykład analizuje konsekwencje nowelizacji prawa odnoszącego się do kontroli i zapobiegania zanieczyszczeniu wód, w oparciu o dane z lat 2003-2011. Uzyskane wyniki pokazują, że akt prawny WPPCL2008 doprowadził do znacznego wzrostu wydajności pracy, zarazem towarzysząca mu zmiana wskaźnika rentowności aktywów nie wpłynęła w znaczący sposób na funkcjonowanie przemysłu odpowiedzialnego za największą część zanieczyszczenia wód. Ponadto wprowadzeniu WPPCL2008 towarzyszył niewielki negatywny wpływ na poziom zatrudnienia w sektorach intensywnie zanieczyszczających wody. Artykuł omawia także aktualnie przygotowywane akty prawne, które mają szanse wyeliminować te niedogodności.

9

Challenges to Sustainability of Resource-exhausted Cities:A Case Study of Lengshuijiang, China

Zuo G., Chen Q.

Problemy Ekorozwoju

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2015

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Vol. 10, nr 1

89--98

EN

Resource-based cities were once the backbone of Chinese economy for decades. When natural resources were depleted, however, these cities become negative assets of China and urgently need sustainable transition. Given the vast number of resource-exhausted cities in China, their success transitions not only mean much to themselves but also have great implications on China’s sustainability. Taking Lengshuijiang, one of the 67 resource-exhausted cities of China, as a case, this article investigated sustainable transition of resource-exhausted cities in Chinese context. Firstly, we reviewed the development problems it faces in the past two decades. Secondly, we examined the countermeasures it took since 2009. Although this article mainly focuses on Lengshuijiang, the findings and discussion will provide insights for other resource-exhausted cities of China and other parts of the word in reviewing their development strategies as most of them are facing similar sustainable challenges.

PL

Miasta bazujące na surowcach stanowiły trzon chińskiej gospodarki od dziesięcioleci. Gdy zasoby naturalne zostały wyczerpane, miasta te stały się ujemnymi aktywami Chin i pilnie potrzebują zrównoważonych przekształceń. Biorąc pod uwagę dużą liczbę takich miast, ich sukces nie tylko będzie ważny dla nich samych, ale odegra również istotną rolę w zrównoważonym rozwoju całych Chin. Jako przykład wybrano Lengshuijiang, jedno z 67 miast, które dotknęło wyczerpanie zasobów, analizując zrównoważoność dokonanych tam przekształceń. Po pierwsze oceniono problemy rozwojowe występujące w ciągu ostatnich dwudziestu lat. Po drugie, zbadano skuteczność środków zaradczych, wprowadzonych w 2009 r. Przykład miasta Lengshuijiang stanowi punkt odniesienia dla strategii rozwojowych innych miast dotkniętych problemem wyczerpania surowców tak w Chinach, jak i w innych państwach świata, ponieważ większość z nich to staje w obliczu podobnych wyzwań.

10

Risk assessment for industrial control systems quantifying availability using mean failure cost (MFC)

Chen Q., Abercrombie R. K., Sheldon F. T.

Journal of Artificial Intelligence and Soft Computing Research

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2015

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Vol. 5, No. 3

205--220

EN

Industrial Control Systems (ICS) are commonly used in industries such as oil and natural gas, transportation, electric, water and wastewater, chemical, pharmaceutical, pulp and paper, food and beverage, as well as discrete manufacturing (e.g., automotive, aerospace, and durable goods.) SCADA systems are generally used to control dispersed assets using centralized data acquisition and supervisory control. Originally, ICS implementations were susceptible primarily to local threats because most of their components were located in physically secure areas (i.e., ICS components were not connected to IT networks or systems). The trend toward integrating ICS systems with IT networks (e.g., efficiency and the Internet of Things) provides significantly less isolation for ICS from the outside world thus creating greater risk due to external threats. Albeit, the availability of ICS/SCADA systems is critical to assuring safety, security and profitability. Such systems form the backbone of our national cyber-physical infrastructure. Herein, we extend the concept of mean failure cost (MFC) to address quantifying availability to harmonize well with ICS security risk assessment. This new measure is based on the classic formulation of Availability combined with Mean Failure Cost (MFC). The metric offers a computational basis to estimate the availability of a system in terms of the loss that each stakeholder stands to sustain as a result of security violations or breakdowns (e.g., deliberate malicious failures).

11

Experimental Investigation on the Compression Behaviours of 3D Angle‑interlock Woven Composites with Carbons Nanotube under High Strain Rates

Ma P, Jiang G, Zhang F, Chen Q, Miao X, Cong H

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 2 (110)

44--50

EN

The compressive properties of 3D angle-interlock woven/epoxy resin composites with various carbon nanotube (CNTs) contents were investigated under quasi-static and high strain rate loading to evaluate the compressive failure modes, which were influenced by various CNT contents and different strain rates. The results indicated that the stress strain curves were strain rate sensitive, and the compressive failure stress of composites with various CNT contents were increased with a change the strain rates and CNT contents. The compressive failure modes of 3D angle-interlock woven composites without CNT tended to be in shear deformation, delamination fibre breakage and matrix crack together, and the failure modes of 3D angle-interlock woven composites with high CNT contents presented delamination and shear deformation.

PL

Badano właściwości ściskające kompozytów 3D wzmacnianych tkaninami o skośnym splocie interlokowym modyfikowanych nanorurkami węglowymi. W celu wyznaczenia uszkodzeń powstałych na skutek ściskania, na które wpływa zawartość nanorurek i szybkości odkształcania, badania przeprowadzono pod obciążeniem quasi-statycznym i przy dużych szybkościach ściskania. Wyniki wykazały, że krzywe ściskania zależały od szybkości odkształcania i zawartości nanorurek. Uszkodzenia mają charakter rozwarstwienia i deformacji pod wpływem naprężeń ścinających.

12

Bifurcation and control for a discrete-time prey–predator model with Holling-IV functional response

Chen Q., Teng Z., Hu Z.

International Journal of Applied Mathematics and Computer Science

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2013

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Vol. 23, no. 2

247--261

EN

The dynamics of a discrete-time predator–prey model with Holling-IV functional response are investigated. It is shown that the model undergoes a flip bifurcation, a Hopf bifurcation and a saddle-node bifurcation by using the center manifold theorem and bifurcation theory. Numerical simulations not only exhibit our results with the theoretical analysis, but also show the complex dynamical behaviors, such as the period-3, 6, 9, 12, 20, 63, 70, 112 orbits, a cascade of period-doubling bifurcations in period-2, 4, 8, 16, quasi-periodic orbits, an attracting invariant circle, an inverse period-doubling bifurcation from the period-32 orbit leading to chaos and a boundary crisis, a sudden onset of chaos and a sudden disappearance of the chaotic dynamics, attracting chaotic sets and non-attracting sets. We also observe that when the prey is in chaotic dynamics the predator can tend to extinction or to a stable equilibrium. Specifically, we stabilize the chaotic orbits at an unstable fixed point by using OGY chaotic control.

13

Modelling and Near-Threshold Computing of Power-Gating Adiabatic Logic Circuits

Hu J., Chen Q.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 7b

277--280

EN

This paper introduces a power-gating scheme appropriate for near-threshold operating of single-phase adiabatic circuits. A transmission gate with MOS bootstrapping scheme is used as the power-gating switch, which is used to reduce energy overhead. CAL (Clocked Adiabatic Logic) circuits are investigated. The analytical model for power-gating adiabatic circuits is constructed, and the energy overhead of the proposed powergating scheme is analyzed in detail. The results show that the proposed power-gating technique is suitable for near-threshold operating.

PL

W artykule wprowadzono schemat bramkowania mocy dla progowej operacji jednofazowych obwodów adiabatycznych. Zaproponowano model analityczny bazujący na układach MOS jako przełącznikach bramkujących.

14

Application of dynamic speckle methods to study thermal denaturation of the albumin

Li X., Tai Y., Nie Z., Chen Q., Li L.

Optica Applicata

|

2011

|

Vol. 41, nr 3

581--591

EN

The process of the thermal denaturation of albumin was studied using dynamic speckle methods, which included the time history of speckle patterns (THSP), the THSP based on wavelet entropy (WE), speckle size measurement and the speckle pattern mean contrast techniques. In experiments, the dynamic speckle pattern sequences produced from the albumin colloid during heat denaturation were obtained using CCD camera. And then, using these dynamic speckle methods, the change of the movement properties of protein particles was analyzed during the heating process. All results show that the protein particles become bigger, their mean free path becomes shorter and the velocity of the Brownian movement becomes slower during the heating process. The experiments prove that dynamic speckle methods are useful tools to investigate the particles motion in solution.

15

Development of a method for comprehensive and quantitative analysis of Yohimbine in Pausinystalia yohimbe by liquid chromatography-ion trap mass spectrometry

Chen Q., Li P., Li B., Yuan F., Li X., Zhu J.

Acta Chromatographica

|

2011

|

Vol. 23, no. 4

629--639

EN

A rapid and sensitive method for the identification and quantification of yohimbine in Pausinystalia yohimbe is described. The method used is liquid chromatography-quadrupole ion trap mass spectrometry (LC-QIT/MS). The yohimbine standard solution was directly infused into the ion trap mass spectrometers (IT/MS) for collecting the MSn spectra. The major fragment ions of yohimbine were confirmed by MSn at m/z 355, 224, 212, and 144, in the positive-ion mode. The possible main fragment ion cleavage pathway was studied. Yohimbine provided good signals corresponding to the protonated molecular ion [M + H]+. The method is reliable and reproducible, and the detection limit is 0.1 ng mL-1. The method was validated in the concentration range 0.1–50 μg mL-1; the intra- and interday precision ranged from 1.36% to 2.73%; and the accuracy was 96.5–108.2%. The mean recovery of yohimbine was 97.1–101% with a relative standard deviation (RSD) <1.93%. The LC-IT/MS method was successfully applied to determine the yohimbine in P. yohimbe.

16

Fault tolerant control of switched nonlinear systems with time delay under asynchronous switching

Xiang Z., Wang R., Chen Q.

International Journal of Applied Mathematics and Computer Science

|

2010

|

Vol. 20, no 3

497-506

EN

This paper investigates the problem of fault tolerant control of a class of uncertain switched nonlinear systems with time delay under asynchronous switching. The systems under consideration suffer from delayed switchings of the controller. First, a fault tolerant controller is proposed to guarantee exponentially stability of the switched systems with time delay. The dwell time approach is utilized for stability analysis and controller design. Then the proposed approach is extended to take into account switched time delay systems with Lipschitz nonlinearities and structured uncertainties. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

17

Phased array optimizing characteristics in HIFU device

Chen Q., Xiong B., Chen Y.

Archives of Acoustics

|

2003

|

Vol. 28, no. 2

109-116

EN

For the high intensity focused ultrasound (HIFU) phased array frequency distribution pattern size and amount of the elements may affect the performance and cost of the HIFU device. In this paper an inner holed spherical shell with 96 transducer elements was designed basing on the Ebbini pseudo-inverse matrix and Penns bioheat equation. The phased array has a lower grating-lobe level and a higher intensity gain suitable for deep heating. The experiments with the array usung 16 elements show that the phased array design produces a large dynamic scan scale with least elements and a high heat focus.