A non-linear continuum damage model was presented based on the irreversible thermodynamics framework developed by LEMAITRE and CHABOCHE. The proposed model was formulated by taking into account the influence of loadin...A non-linear continuum damage model was presented based on the irreversible thermodynamics framework developed by LEMAITRE and CHABOCHE. The proposed model was formulated by taking into account the influence of loading frequency on fatigue life. The parameters H and c are constants for frequency-independent materials, but functions of cyclic frequency for frequency-dependent materials. In addition, the expression of the model was discussed in detail at different stress ratios （R）. Fatigue test data of AlZnMgCu1.5 aluminium alloy and AMg6N alloy were used to verify the proposed model. The results showed that the model possesses a good ability of predicting fatigue life at different loading frequencies and stress ratios.展开更多
An efficient way to design a down-converter assembly for the Ka-band millimeter system is presented, in which dielectric resonators （DR＇s） are adopted in the Schottky barrier diode image recovery mixer and the loca...An efficient way to design a down-converter assembly for the Ka-band millimeter system is presented, in which dielectric resonators （DR＇s） are adopted in the Schottky barrier diode image recovery mixer and the local oscillator （LO）. DR structures guarantee high frequency stability with an acceptable volume. The configurations of low noise amplifier, mixer and oscillator in the assembly are described and fabricated to estimate the chain performance. According to the verification results, the assembly exhibits the noise figure of less than 5 dB over 1 GHz frequency range, and the single-sideband phase noise （200 kHz offset from carrier frequency） of - 70 dBc/Hz. Utilizing the DR structure, the frequency stability of the local oscillator is less than 60 × 10^-6/℃.展开更多
AIM： To establish an ideal model of multiple organ injury of rats with severe acute pancreatitis （SAP）.METHODS： SAP models were induced by retrograde injection of 0.1 mL/100 g 3.5% sodium taurocholate into the bil...AIM： To establish an ideal model of multiple organ injury of rats with severe acute pancreatitis （SAP）.METHODS： SAP models were induced by retrograde injection of 0.1 mL/100 g 3.5% sodium taurocholate into the biliopancreatic duct of Sprague-Dawley rats. The plasma and samples of multiple organ tissues of rats were collected at 3, 6 and 12 h after modeling. The ascites volume, ascites/body weight ratio, and contents of amylase, endotoxin, endothelin-1 （ET-1）, nitrogen monoxidum （NO）, phospholipase A2 （PLA2）, tumor necrosis factor-α （TNF-α）, interleukin-6 （IL-6） in plasma were determined. The histological changes of multiple organs were observed under light microscope.RESULTS： The ascites volume, ascites/body weight ratio, and contents of various inflammatory mediators in blood were higher in the model group than in the sham operation group at all time points [2.38 （1.10）, 2.58 （0.70）, 2.54 （0.71） vs 0.20 （0.04）, 0.30 （0.30）, 0.22 （0.10） at 3, 6 and 12 h in ascites/body weight ratio; 1582 （284）, 1769 （362）, 1618 （302） （U/L） vs 5303 （1373）, 6276 （1029）, 7538 （2934） （U/L） at 3, 6 and 12 h in Amylase; 0.016 （0.005）, 0.016 （0.010）, 0.014 （0.015） （EU/mL） vs 0,053 （0.029）, 0.059 （0.037）, 0.060 （0.022） （EU/mL） at 3, 6 and 12 h in Endotoxin; 3.900 （3.200）, 4.000 （1.700）, 5.300 （3.000） （ng/L） vs 41.438 （37.721）, 92.151 （23.119）, 65.016 （26.806） （ng/L） at 3, 6 and 12 h in TNF-α, all P 〈 0.01]. Visible congestion, edema and lamellar necrosis and massive leukocytic infiltration were found in the pancreas of rats of model group. There were also pathological changes of lung, liver, kidney, ileum, lymphonode, thymus, myocardium and brain.CONCLUSION： This rat model features reliability, convenience and a high achievement ratio. Complicated with multiple organ injury, it is an ideal animal model of SAR展开更多
文摘A non-linear continuum damage model was presented based on the irreversible thermodynamics framework developed by LEMAITRE and CHABOCHE. The proposed model was formulated by taking into account the influence of loading frequency on fatigue life. The parameters H and c are constants for frequency-independent materials, but functions of cyclic frequency for frequency-dependent materials. In addition, the expression of the model was discussed in detail at different stress ratios （R）. Fatigue test data of AlZnMgCu1.5 aluminium alloy and AMg6N alloy were used to verify the proposed model. The results showed that the model possesses a good ability of predicting fatigue life at different loading frequencies and stress ratios.
文摘An efficient way to design a down-converter assembly for the Ka-band millimeter system is presented, in which dielectric resonators （DR＇s） are adopted in the Schottky barrier diode image recovery mixer and the local oscillator （LO）. DR structures guarantee high frequency stability with an acceptable volume. The configurations of low noise amplifier, mixer and oscillator in the assembly are described and fabricated to estimate the chain performance. According to the verification results, the assembly exhibits the noise figure of less than 5 dB over 1 GHz frequency range, and the single-sideband phase noise （200 kHz offset from carrier frequency） of - 70 dBc/Hz. Utilizing the DR structure, the frequency stability of the local oscillator is less than 60 × 10^-6/℃.
基金technological foundation project of Traditional Chinese Medicine Science of Zhejiang province, No. 2003C130 No. 2004C142+4 种基金foundation project for medical science and technology of Zhejiang provinc, No. 2003B134grave foundation project for technological and development of Hangzhou, No. 2003123B19intensive foundation project for technology of Hangzhou, No. 2004Z006foundation project for medical science and technology of Hangzhou, No. 2003A004foundation project for technology of Hangzhou, No. 2005224
文摘AIM： To establish an ideal model of multiple organ injury of rats with severe acute pancreatitis （SAP）.METHODS： SAP models were induced by retrograde injection of 0.1 mL/100 g 3.5% sodium taurocholate into the biliopancreatic duct of Sprague-Dawley rats. The plasma and samples of multiple organ tissues of rats were collected at 3, 6 and 12 h after modeling. The ascites volume, ascites/body weight ratio, and contents of amylase, endotoxin, endothelin-1 （ET-1）, nitrogen monoxidum （NO）, phospholipase A2 （PLA2）, tumor necrosis factor-α （TNF-α）, interleukin-6 （IL-6） in plasma were determined. The histological changes of multiple organs were observed under light microscope.RESULTS： The ascites volume, ascites/body weight ratio, and contents of various inflammatory mediators in blood were higher in the model group than in the sham operation group at all time points [2.38 （1.10）, 2.58 （0.70）, 2.54 （0.71） vs 0.20 （0.04）, 0.30 （0.30）, 0.22 （0.10） at 3, 6 and 12 h in ascites/body weight ratio; 1582 （284）, 1769 （362）, 1618 （302） （U/L） vs 5303 （1373）, 6276 （1029）, 7538 （2934） （U/L） at 3, 6 and 12 h in Amylase; 0.016 （0.005）, 0.016 （0.010）, 0.014 （0.015） （EU/mL） vs 0,053 （0.029）, 0.059 （0.037）, 0.060 （0.022） （EU/mL） at 3, 6 and 12 h in Endotoxin; 3.900 （3.200）, 4.000 （1.700）, 5.300 （3.000） （ng/L） vs 41.438 （37.721）, 92.151 （23.119）, 65.016 （26.806） （ng/L） at 3, 6 and 12 h in TNF-α, all P 〈 0.01]. Visible congestion, edema and lamellar necrosis and massive leukocytic infiltration were found in the pancreas of rats of model group. There were also pathological changes of lung, liver, kidney, ileum, lymphonode, thymus, myocardium and brain.CONCLUSION： This rat model features reliability, convenience and a high achievement ratio. Complicated with multiple organ injury, it is an ideal animal model of SAR
