Two parameters,block spectrum intensity Seq and spectrum shape factor a,which describe the characteristics of the loading block spectrum are defined,and the relationship between the parameters and fatigue crack propag...Two parameters,block spectrum intensity Seq and spectrum shape factor a,which describe the characteristics of the loading block spectrum are defined,and the relationship between the parameters and fatigue crack propagation behaviours is investigated.It is shown that the spectrum intensity is an 'average drive force' of fatigue crack propagation,and the variance of fatigue crack size at a given fatigue life is closely related to the spectrum shape factor α.展开更多
Some experimental investigations were carried out with the samples of metal Al and AlCl3 solutions. It is found that the spectrum varies with the change of experimental setup parameters both in Al bulk material and Al...Some experimental investigations were carried out with the samples of metal Al and AlCl3 solutions. It is found that the spectrum varies with the change of experimental setup parameters both in Al bulk material and AlCl3 solutions. The temporal evolution properties and the affection of incident laser energy on the laser-induced breakdown spectroscopy (LIBS) signals were also discussed. The lifetime of laser induced plasma in AlCl3 solutions is found to be about 30 ns which is much shorter than in solid materials. Compared with the solid samples, the Al LIBS signals in AlCl3 solutions require higher laser energy. Under the optimized conditions, the detection limit of Al in AlCl3 solution was determined to be around 1000 ppm for the system we used.展开更多
The displacements and geometry of the rock blocks and the properties of the rock struc-ture play an important role in the stability of tunnels.Based on the key block model,the dynamic instability analysis of undergrou...The displacements and geometry of the rock blocks and the properties of the rock struc-ture play an important role in the stability of tunnels.Based on the key block model,the dynamic instability analysis of underground tunnel subjected to intensive short-time compressional wave was conducted.The instability of the tunnel caused by the spallation and the inertial effect was distin-guished.And the influence of the roof contour curvature of tunnel was also determined.展开更多
Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam (Dioscorea spp.) production. Identifying yield- and maturity-related traits and breeding for them w...Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam (Dioscorea spp.) production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits: time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight (tuber yield), tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. (water yam) on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.展开更多
Objective To investigate the relationships between vascular factors and plaque morphology in the patients with acute coronary syndrome(ACS). Methods Intravascular ultrasound(lVUS) was performed on 56 consecutively...Objective To investigate the relationships between vascular factors and plaque morphology in the patients with acute coronary syndrome(ACS). Methods Intravascular ultrasound(lVUS) was performed on 56 consecutively enrolled patients with ACS. Cytometric bead array for seven vascular factors(sPE,t-PA, MCP-1, IL-8,1L-6,sVCAM-1, and sCD40L) was measured by cytometry. The others biomarkers were tested by ELISA or biochemistry. Differences in bio-factors were compared between vulnerable plaque and non- vulnerable plaque groups, accte myocardial infarction (AMI) and ustable angina (UA) patients, and occurring plaque rupture. The relationship between the parameters of morphology and vascular factors was analyzed. Results There were positive correlations between sVCAM-lsPE, sVCAM-I-sCD40L, sCD40L-sPE, IL-6-ILS,ILS-MCP1, and MCPI-sVCAM-1; CRP (18.868±4.907mg/L vs 5.806±3.553 mg/L)and IL-6 (19.5 pg/ml [9.2 - 44.6 pg/ml]vs 5.3 pg/ml [2.3- 13.4 pg/ml])were elevated in the vulnerable plaque group(P 〈0.05). sCD40L(473.82± 126.11 vs 237.94± 34.78 pg/ml),sPE (107.21±39.90 vs 49.06 ±5.61ug/L) and MCP-1(132.42 ± 17.85 vs 127.17±13.27 pg/ml) were increased in the plaque rupture group(P 〈 0.05);There was correlation between tPA and plaque morphology(P 〈 0.05). Increases in sCD40L, MCP-1, sPE, and TC were independent factors for plaque rupture. Conclusions IL-6 and CRP may be biomarkers for vulnerable plaque and for diagnosis ofAMI, sCD40L, MCP-1 and sPE are potential markers when for plaque rupture patient present with severe ACS.展开更多
In this paper, we investigate the global controllability of a class of n-dimensional affine nonlinear systems with n- 1 controls and constant control matrix. A necessary and sufficient condition for its global control...In this paper, we investigate the global controllability of a class of n-dimensional affine nonlinear systems with n- 1 controls and constant control matrix. A necessary and sufficient condition for its global controllability has been obtained by using the methods recently developed. Furthermore, we generalize the above result to a class of affine nonlinear systems with a block-triangular-like structure. Finally, we will give three examples to show the applications of our results.展开更多
文摘Two parameters,block spectrum intensity Seq and spectrum shape factor a,which describe the characteristics of the loading block spectrum are defined,and the relationship between the parameters and fatigue crack propagation behaviours is investigated.It is shown that the spectrum intensity is an 'average drive force' of fatigue crack propagation,and the variance of fatigue crack size at a given fatigue life is closely related to the spectrum shape factor α.
基金This work was supported by Hi-Tech Research and DevelopmentProgram of China (2002AA615170)Natural Science Foundationof Anhui (2001KJ116ZD)Natural Science Foundation ofShandong (Y2006A26)
文摘Some experimental investigations were carried out with the samples of metal Al and AlCl3 solutions. It is found that the spectrum varies with the change of experimental setup parameters both in Al bulk material and AlCl3 solutions. The temporal evolution properties and the affection of incident laser energy on the laser-induced breakdown spectroscopy (LIBS) signals were also discussed. The lifetime of laser induced plasma in AlCl3 solutions is found to be about 30 ns which is much shorter than in solid materials. Compared with the solid samples, the Al LIBS signals in AlCl3 solutions require higher laser energy. Under the optimized conditions, the detection limit of Al in AlCl3 solution was determined to be around 1000 ppm for the system we used.
基金Supported by Beijing Natural Science Foundation and Key Program of Scientific Planning of Beijing Education Committee (No.KZ200810016007)
文摘The displacements and geometry of the rock blocks and the properties of the rock struc-ture play an important role in the stability of tunnels.Based on the key block model,the dynamic instability analysis of underground tunnel subjected to intensive short-time compressional wave was conducted.The instability of the tunnel caused by the spallation and the inertial effect was distin-guished.And the influence of the roof contour curvature of tunnel was also determined.
文摘Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam (Dioscorea spp.) production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits: time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight (tuber yield), tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. (water yam) on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.
文摘Objective To investigate the relationships between vascular factors and plaque morphology in the patients with acute coronary syndrome(ACS). Methods Intravascular ultrasound(lVUS) was performed on 56 consecutively enrolled patients with ACS. Cytometric bead array for seven vascular factors(sPE,t-PA, MCP-1, IL-8,1L-6,sVCAM-1, and sCD40L) was measured by cytometry. The others biomarkers were tested by ELISA or biochemistry. Differences in bio-factors were compared between vulnerable plaque and non- vulnerable plaque groups, accte myocardial infarction (AMI) and ustable angina (UA) patients, and occurring plaque rupture. The relationship between the parameters of morphology and vascular factors was analyzed. Results There were positive correlations between sVCAM-lsPE, sVCAM-I-sCD40L, sCD40L-sPE, IL-6-ILS,ILS-MCP1, and MCPI-sVCAM-1; CRP (18.868±4.907mg/L vs 5.806±3.553 mg/L)and IL-6 (19.5 pg/ml [9.2 - 44.6 pg/ml]vs 5.3 pg/ml [2.3- 13.4 pg/ml])were elevated in the vulnerable plaque group(P 〈0.05). sCD40L(473.82± 126.11 vs 237.94± 34.78 pg/ml),sPE (107.21±39.90 vs 49.06 ±5.61ug/L) and MCP-1(132.42 ± 17.85 vs 127.17±13.27 pg/ml) were increased in the plaque rupture group(P 〈 0.05);There was correlation between tPA and plaque morphology(P 〈 0.05). Increases in sCD40L, MCP-1, sPE, and TC were independent factors for plaque rupture. Conclusions IL-6 and CRP may be biomarkers for vulnerable plaque and for diagnosis ofAMI, sCD40L, MCP-1 and sPE are potential markers when for plaque rupture patient present with severe ACS.
基金The research was supported by the National Natural Science Foundation of China under Grant No. 50525721, 60221301, and 60334040, and China Postdoctoral Science Foundation under Grant No. 20060390470. Acknowledgment The authors would like to thank Prof. Lei GUO for his very valuable discussions and suggestions.
文摘In this paper, we investigate the global controllability of a class of n-dimensional affine nonlinear systems with n- 1 controls and constant control matrix. A necessary and sufficient condition for its global controllability has been obtained by using the methods recently developed. Furthermore, we generalize the above result to a class of affine nonlinear systems with a block-triangular-like structure. Finally, we will give three examples to show the applications of our results.