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521.
Dynamic Responses Analysis of a Building Structure Subjected to Ground Shock from a Tunnel Explosion
TIAN Li LI Zhongxian HAO Hong 《天津大学学报(英文版)》2006,12(B09):100-106
Dynamic responses of a multi-storey building without or with a sliding base-isolation device for ground shock induced by an in-tunnel explosion are numerically analyzed. The effect of an adjacent tunnel in between the building and the explosion tunnel, which affects ground shock propagation, is considered in the analysis. Different modeling methods, such as the eight-node equal-parametric finite element and mass-lumped system, are used to establish the coupling model consisting of the two adjacent tunnels, the surrounding soil medium with the Lysmer viscous boundary condition, and the multi-storey building with or without the sliding base-isolation device. In numerical calculations, a continuous friction model, which is different from the traditional Coulomb friction model, is adopted to improve the computational efficiency and reduce the accumulated errors. Some example analyses are subsequently performed to study the response characteristics of the building and the sliding base-isolation device to ground shock. The effect of the adjacent tunnel in between the building and the explosion tunnel on the ground shock wave propagation is also investigated. T.he final conclusions based on the numerical results will provide some guidance in engineering practice. 相似文献
522.
In order to improve efficiency of virtual enterprise, a manufacturing grid and multilevel manufacturing system of virtual enterprise is built up. When selecting member enterprises and task assignment based on the manufacturing grid, key activities are assigned to the suitable critical member enterprises by task decomposition, enterprise node searching and characteristic matching of manufacturing resources according to the characteristic matching strategy. By task merger, some ordinary activities are merged with corresponding key activities and assigned to corresponding critical member enterprises. However, the other ordinary activities are assigned to the related ordinary member enterprises with enterprise node searching and characteristic matching of manufacturing resources. Finally, an example of developing the artificial hip joint in the virtual enterprise is used to demonstrate that efficiency of the virtual enterprise is improved by using the manufacturing grid and the proposed strategies for member enterprise selection and task assignment. 相似文献
523.
A hybrid neural network system for prediction and recognition of promoter regions in human genome 总被引:1,自引:0,他引:1
INTRODUCTION The publication and preliminary analysis of thehuman genome sequence (Lander et al., 2001; Venteret al., 2001) marks a significant milestone in the fieldof molecular biology. One of the main goals of theHuman Genome Project is the characterization, an-notation?recognition and categorization of genesfrom human genome to serve as a periodic table forbiomedical research (Lander, 1996). In the past fewyears, many efforts have been devoted to gene anno-tations. The Nation… 相似文献
524.
INTRODUCTION Zeolite membranes have been investigated formany years due to their promising applications inseparations (Tavolaro and Drioli, 1999) and mem-brane reactors (Coronas and Santamaria, 1999). Oneof the challenges in the preparation of zeolite mem-branes is the control of the crystal orientation, espe-cially for zeolites that have an anisotropic porestructure (Caro et al., 2000). An ideal case is that thechannels in the zeolite crystals are perpendicular tothe support surfa… 相似文献
525.
Social functioning and adjustment in Chinese children: the imprint of historical time 总被引:4,自引:0,他引:4
This study examined, in 3 cohorts (1990, 1998, and 2002) of elementary school children (M age=10 years), relations between social functioning and adjustment in different phases of the societal transition in China. Data were obtained from multiple sources. The results indicate that sociability-cooperation was associated with peer acceptance and teacher-rated competence, whereas aggression was associated with social and school difficulties in all 3 cohorts. The effect of different social contexts was reflected mainly in the relations between shyness-sensitivity and adjustment. Whereas shyness was associated with social and academic achievement in the 1990 cohort, the associations became weaker or nonsignificant in the 1998 cohort. Furthermore, shyness was associated with peer rejection, school problems, and depression in the 2002 cohort. 相似文献
526.
The short report will be focused on helping our students to understand commonly used conventional and cutting edge cytogenetic techniques and their clinical applications, the advances and drawbacks of each technique, and how to pick the right test(s) for a specific patient in order to achieve a proper diagnosis efficiently and economically. 相似文献
527.
Objective: To investigate the dynamics of vascular volume and the plasma dilution of lactated Ringer's solution in patients during the induction of general and epidural anesthesia. Methods: The hemodilution of i.v. infusion of 1000 ml of lactated Ringer's solution over 60 min was studied in patients undergoing general (n=31) and epidural (n= 22) anesthesia. Heart rate, arterial blood pressure and hemoglobin (Hb) concentration were measured every 5 rain during the study. Surgery was not started until the study period had been completed. Results: General anesthesia caused the greater decrease of mean arterial blood pressure (MAP) (mean 15% versus 9%; P〈0.01) and thereby followed by a more pronounced plasma dilution, blood volume expansion (VE) and blood volume expansion efficiency (VEE). A strong linear correlation between hemodilution and the reduction in MAP (r=-0.50;P〈0.01) was found. At the end of infusion, patients undergoing general anesthesia retained 47% (SD 19%) of the infused fluid in the circulation, while epidural anesthesia retained 29% (SD 13%) (P〈0.001). Correspondingly, a fewer urine output (mean 89 ml versus 156 ml; P〈0.05) and extravascular expansion (454 ml versus 551 ml; P〈0.05) were found during general anesthesia. Conclusion: We concluded that the induction of general anesthesia caused more hemodilution, volume expansion and volume expansion efficiency than epidural anesthesia, which was triggered only by the lower MAP. 相似文献
528.
529.
Ye M Cao SQ Jiang ST Pan LJ Luo SZ Li XJ 《Journal of Zhejiang University. Science. B》2006,7(1):20-27
INTRODUCTION A large number of Lachnum species have been reported from diverse regions of the world (Dennis, 1949; 1961; Galán and Raitviir, 1994; Haines, 1980; 1992; Haines and Dumont, 1984; Haines and Kaneko, 1984; Sharma, 1986; Singh, 1975; Spooner, 1987; Tai, 1979; Teng, 1934; 1963; Wu et al., 1998; Wu and Haines, 1999; Zhuang and Hyde, 2001). The earliest records of Lachnum in China dated back to 1934 when the Chinese mycologist Teng (1934) reported two species from Zhejian… 相似文献
530.
We observed in a pilot study that there was a transient elevation of brain natriuretic peptide (BNP) level shortly after the transplantation in the patient with ischemic heart failure, which is unexplainable by the simultaneous increase of the cardiac output and six-minute walk distance. Similar findings were observed in the phase I trial. We postulated on the basis of the finding of Fukuda in vitro that this transient elevation of BNP level against the improvement of cardiac function and exercise capacity might indicate cardiomyogenesis in patients after mesenchymal stem cell transplantation. Further study is warranted to verify the hypothesis. 相似文献