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Coal rock creep is an inevitable phenomenon in coal mining, fluid seepage is involved in coal rock creep in coal mine, and coal rock creep and fluid flow interact. To determine the coal rock creep–seepage law, in this paper, CSCG-160-type gravity hydraulic constant load creep seepage test system developed by China University of Mining & Technology (Beijing) is used to carry out creep seepage test with step loaded axle load in certain condition of confining pressure for raw coal rock sample; in the test, coal rock-related deformation (axial strain, volumetric strain) in the creep process is measured and seepage is recorded. By analysis of the test result, the creep deformation – seepage law during coal rock creep seepage is obtained. The study result of very important practical guiding significance for dynamic disaster and water damage prevention and control of gas in coal mine.

A novel dual-linearly-polarized microstrip antenna array with series-feeding configuration is presented. Dual-linear polarization is excited by upper side-feeding and lower aperture-coupled feeding. Meanwhile, the series-feeding configuration is realized by a composite right/left-handed transmission line. Compared with the traditional parallel and series-fed configuration, this array is of simple structure, small area, and high efficiency. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1366–1369, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21678

Coal spontaneous combustion is the main disaster of coal mine, furthermore most of them happen in the goaf. Distribution of "three zones" of spontaneous combustion reflects the state of oxidation temperature increasing in goaf, which is the base of spontaneous combustion prevention and control in goaf. This paper analyzed critical value of the "threezones" partition methods in goaf which are based on air leakage velocity and oxygen concentration, propose a new method of combining these two indexes. The authors simulate and calculate the distribution the velocity of air leakage and oxygen concentration in goaf of 2108 fully mechanized caving face of gucheng coal mine in Shandong by used the established model of spontaneous combustion in goaf under the moving coordinates, partition the "three zones". The results provide a theoretical basis for prediction and prevention of spontaneous combustion in goaf.

Based on the structure of left-handed transmission line (LH-TL), a novel phase shifter with higher power capacity is designed here. In the present structure, switches of phase shifters are mounted on fingers of LH-TLs, so the electric current through a single switch is only a fraction of that through the whole phase shifter. As a result, the power capacity of present phase shifter can be greatly improved. Changing the state of fingers of LH-TLs by controlling the switches, different phase shifts can be achieved. Besides its higher power capacity, present phase shifter possesses other advantages such as low cost, small size and easy fabrication. Finally, phase shifters of 11.25deg, 22.5deg and 45deg have been designed as examples.

A novel dual-linearly-polarized microstrip antenna array with series fed configuration is presented. Dual-linear-polarization is excited by upper side-feeding and lower aperture-coupled feeding. Meanwhile, the series-feeding configuration is realized by a composite right/left-handed transmission line. Compared with the traditional design, this array is of simple structure, small area.

To compare the diagnostic value of soluble intercellular adhesion molecule 1 (sICAM-1) with that of c-reactive protein (CRP) for detecting chorioamnionitis (CAM) in serum of women with premature rupture of membranes (PROM), 55 pregnant women with PROM, including 18 pregnant women with preterm premature rupture of membranes (PPROM) and 20 normal pregnant women at term (TPROM) were studied. Maternal serum were measured by Sandwish enzyme-linked immunoabsorbent assay (ELISA) for sICAM. CAM was histologically confirmed after delivery. The results revealed that (1) maternal serum levels of sICAM-1 and CRP were significantly higher in women with PROM than those without it; (2) maternal serum levels of sICAM-1 and CRP were significantly higher in women with CAM than those without it; (3) serum levels of sICAM-1 in PPROM women were similar to those in TPROM women, whereas serum levels of CRP in PPROM women were significantly higher than those in TPROM women; (4) the sensitivity, specificity, positive predictive value, negative predictive value, Kappa index and area under receiver operating characteristic (ROC) curve of maternal serum sICAM-1 (cutoff 104.7 ng/ml) and CRP (cutoff 1.03 mg/dl) for diagnosing CAM were 100%, 91.2%, 87.5%, 100%, 0.20, 0.995 and 81.0%, 73.5%, 65.4%, 86.2%, 0.13, 0.811, respectively; (5) among the mild histological CAM group, severe histological CAM group and clinical CAM group, the difference in maternal serum levels of sICAM-1 were significantly (P