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In this paper, bridge alignment control with considering dynamic train loads was experimentally and theoretically investigated. Analytical process of bridge dynamics and the self-adaptive Kalman filter bridge alignment control method with considering the dynamic train loads were briefly introduced. The static measurement, the dynamic test, the field alignment measurement as well as the finite element analysis (FEA) of the second longest rail transit cable-stayed bridge in the world were carried out. Based on the results, the train dynamic load effect on the bridge alignment was obtained quantitatively. Subsequently, alignment control of the rail transit bridge with considering this effect using a self-adaptive Kalman filter method was analyzed. The results show that: (a) the dynamic train loads have effects on alignment control of the bridge and therefore cannot be neglected; (b) the self-adaptive Kalman filter method is applicable and reliable for alignment control of bridges during construction. The analytical method and whole process contribute to develop a related specification and further engineering applications.  相似文献   
2.
长沙黄兴生态工业园区规划   总被引:1,自引:0,他引:1  
生态工业园区已经引起世界各国的关注和大力推广,并有许多成功的范例,我国近两年来也非常重视,并已开展了一些工作。本文以工业生态学为指导,结合湖南省长沙县的工业和资源优势,构建了一个以四大产业为主导,虚实结合的新型生态工业园区。通过物质、能量和水的集成实现社会、经济、环境利益相协调和废物排放的最小化。  相似文献   
3.
In this study, two casting speeds of 10 and 30 r/min were used in vertical twin-roll casting(TRC) to obtain Mg-rare earth(MgRE) alloys, and their microstructures, corrosion behaviours and in vivo bone reactions were investigated in detail. The results indicated that the roll-castings of TRC-30 r/min exhibited a finer grain size and higher volume fraction of non-crystallization than those in castings of TRC-10 r/min. Moreover, the results of electrochemical impedance spectroscopy(EIS) and potentiodynamic polarization indicated that the castings of TRC-30 r/min displayed a higher corrosion resistance compared with those in the castings of TRC-10 r/min. Animal tests showed that a higher degree of newly formed bone tissues was achieved by implants of TRC-30 r/min. Additionally, in vivo tests displayed that degradation properties of the TRC-30-r/min implants were better than those of the TRC-10-r/min implants; furthermore, the degradation layer was a two-layer structure, and P and Ca were enriched in the outer degradation layer. In summary, these findings elucidated that casting speed has a substantial effect on the microstructure and degradation property of Mg-based implants, and the degradation property performs better with increased casting speed.  相似文献   
4.
生态工业园区的物质集成   总被引:1,自引:0,他引:1  
主要研究内容是在生态工业园区规划和建设过程中对园区企业进行物质集成的方法,以减少园区有害物质的使用和废物的排放。企业减少污染排放主要有三种途径:减量化、再利用和废物再循环。考虑这三种途径分别建立企业多种选择的过程方案,并在园区层次上,将企业各种方案组合成物质集成的超结构网络模型。本文提出了物质集成模型的变量表达方法,分析了物质集成模型的约束条件和目标函数,构建了物质集成的一般性方法。以某工业园区氯元素的集成为例,说明物质集成在园区建设中的应用。  相似文献   
5.
采用有限元软件ANSYS参数设计语言(APDL)实现复合材料薄壁圆柱壳结构在线性分布温度场作用下的非线性热振动特性分析。计算不同约束条件、不同铺层方式和铺层层数的复合材料薄壁圆柱壳在线性温度场作用下的各阶固有频率,分析边界约束、铺层角度及铺层层数对结构热振动频率的影响。结果表明,温度效应、边界约束、铺层层数显著影响结构的固有频率,适当的铺层角度会改变结构的固有频率,不同的铺层方式对结构固有频率影响程度不同。这些结论将对复合材料结构设计、抗热设计有一定的指导作用。  相似文献   
6.
Mean-variance relationship (MVR), nowadays agreed in power law form, is an important function. It is currently used by traffic matrix estimation as a basic statistical assumption. Because all the existing papers obtain MVR only through empirical ways, they cannot provide theoretical support to power law MVR or the definition of its power exponent. Furthermore, because of the lack of theoretical model, all traffic matrix estimation methods based on MVR have not been theoretically supported yet. By observing both our laboratory and campus network for more than one year, we find that such an empirical MVR is not sufficient to describe actual network traffic. In this paper, we derive a theoretical MVR from ON/OFF model. Then we prove that current empirical power law MVR is generally reasonable by the fact that it is an approximate form of theoretical MVR under specific precondition, which can theoretically support those traffic matrix estimation algorithms of using MVR. Through verifying our MVR by actual observation and public DECPKT traces, we verify that our theoretical MVR is valid and more capable of describing actual network traffic than power lawMVR. Supported by the National Basic Research Program of China (Grant No. G2005CB321901)  相似文献   
7.
CANDECOMP/PARAFAC (CP) tensor factorization is an efficient technique for incomplete tensor-data processing through capturing the multilinear latent factors. Based on the incorporate a sparsity-inducing prior over multiple latent factors and appropriate hyper-priors over all hyper-parameters, a Bayesian-based hierarchical probabilistic CP factorization model could be formed. By this way, the rank of the incomplete tensor can be determined automatically. In this paper, we explored the tensor completion method in processing incomplete multidimensional electroencephalogram (EEG) and magnetic resonance imaging (MRI) clinical data. The empirical results indicated that the Bayesian CP tensor factorization of incomplete data method can effectively recover EEG signal with missing data and denoised the noisy MRI data.  相似文献   
8.
The operating instability of a dual compensation chamber loop heat pipe (DCC-LHP) including temperature hysteresis, reverse flow and temperature oscillation is described and explained in this paper. Test results indicate that the steady state operating temperature under the variable conductance mode is not the same during the power cycle tests with the same heat load, and it is lower during the power reduction cycle than that during the power increase cycle. Orientation has an effect on the heat load range when temperature hysteresis occurs, and the effect of power variation amplitude can be ignored. Reverse flow tends to occur in some of the startups at low heat loads, even if vapor existed in the vapor grooves initially, which is caused by a higher pressure inside the wick due to evaporation in the evaporator core or vapor penetration into it. Temperature oscillation tends to occur in some of the startups at low head loads or some steady-state operations at high heat loads. Especially when the compensation chamber with the bayonet through is above the evaporator, the incidence rate of temperature oscillation is high. Supported by the National Natural Science Foundation of China (Grant No. 50676006)  相似文献   
9.
提出一种基于波传播法识别子结构连接界面刚度和阻尼的新方法。以子结构在平面内的弯曲振动为例,将单元的状态变量与波模式联系起来。通过单元波幅系数的识别,得到连接界面的位移和力向量,再由结点上位移连续及力平衡条件,求得连接界面各个自由度上的动刚度。在识别过程中,将动刚度分离为实部和虚部,以便于连接刚度和阻尼的独立识别。为了提高识别精度,选择一定的频率范围,在每一频率下求得连接界面的刚度和阻尼,最后求出统计平均值作为界面的连接参数。数值仿真算例表明本方法具有良好的识别精度和数值稳定性,是一种极有潜力的参数辨识方法。  相似文献   
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