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1.
该项目始于2009年的赫尔辛基倡议.赫内萨里以前是海滨工业区,现在正逐渐向居民区发展.这里有个港口,该区域的新功能亟待开发,城市希望用新的功能激活该地区,并为游客提供富有吸引力的新景点. 相似文献
2.
N. Y. Bailey S. Hibberd H. Power M. V. Tretyakov 《Journal of Engineering Mathematics》2018,112(1):17-35
Motivated by ongoing developments in aero-engine technology, a model for a coupled gas-lubricated bearing is developed in terms of an extended dynamical system. A slip boundary condition, characterised by a slip length, is incorporated on the bearing faces which can be relevant for operation in non-ideal extreme conditions, notably where external vibrations or disturbances could destabilise the bearing. A modified Reynolds equation is formulated to model the gas flow, retaining the effects of centrifugal inertia which is increasingly important for high-speed operation, and is coupled to the structural equations; spring-mass-damper systems model the axial stator and rotor displacements. A novel model is developed corresponding to a bearing experiencing an external random force to evaluate the resulting induced displacements of the bearing components. The minimum face clearance is obtained from a mapping solver for the modified Reynolds equation and structural equations simultaneously. In the case of random excitations, the solver is combined with a Monte Carlo technique. Evaluation of the average value of the minimum gap and the probability of the gap reaching a prescribed tolerance are provided. Extensive insight is given on the effect of key bearing parameters on the corresponding bearing dynamics. 相似文献
3.
中国抗癌协会肿瘤介入学专业委员会上海市抗癌协会实体肿瘤聚焦诊疗专业委员会 《工业加热》2018,(7):603-607
影像导引肝脏恶性肿瘤多模态消融治疗是以医学影像技术为导引,在冷冻消融与热消融交替转换过程中,通过对病灶区温度精准控制和消融过程定量规划,彻底破坏原位肿瘤细胞及其循环系统,同时最大程度释放活性肿瘤抗原,从而达到控制肝脏恶性肿瘤复发转移的目的。为规范肝脏恶性肿瘤多模态消融治疗技术操作,便于不同层级医院开展实施,确保医疗安全和临床疗效,中国抗癌协会肿瘤介入学专业委员会和上海市抗癌协会实体肿瘤聚焦诊疗专业委员会组织国内肿瘤治疗领域的多学科专家共同参与,认真讨论,最终达成本共识。 相似文献
4.
In this paper,we investigate the matched filter based spectrum sensing in a more reasonable cognitive radio(CR) scenario when the primary user(PU) has more than one transmit power levels,as regulated in most standards,i.e.,IEEE 802.11 Series,GSM,LTE,LTE-A,etc.This new multiple primary transmit power(MPTP) scenario is specialized by two different targets:detecting the presence of PU and identifying the power level.Compared to the traditional binary sensing where only the presence of PU is checked,SU may attain more information about the primary network(making CR more "intelligent") and design the subsequent optimization strategy.The key technology is the multiple hypothesis testing as opposed to the traditional binary hypothesis testing.We discuss two situations under whether the channel phase is known or not,and we derive the closed form solutions for decision regions and several performance metrics,from which some interesting phenomenons are observed and the related discussions are presented.Numerical examples are provided to corroborate the proposed studies. 相似文献
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总结大同煤矿集团公司ZY5000/14/23型二柱掩护式液压支架设计的经验,着重阐述了针对近距离煤层“两硬”条件设计支架的技术思路,介绍了支架的性能、结构特点及生产使用情况。 相似文献
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In order to improve vibration mills grinding effect and increase productive efficiency, prime factors of vibration mills were gained much attention. The purpose of this study is to reveal product size distribution and grinding dynamics of vibration mills by orthogonal experi-ments. The metallurgical refractory materials were used as research object. In order to explore the relationships between grinding effect and primary factors, lots of milling experiments were carried out. Based on the results, the conclusions can be summarized: as time runs, the size distri-bution shows exponential trend, and range becomes more and more narrow. Also the quantitative analysis result between grinding effect and primary factors was obtained by non-linear regres-sion: high frequency, high amplitude and low fill ratio can increase grinding speed. 相似文献
9.
介绍了双柱塞砂浆泵的工作原理,通过对采用摆动滚子从动件的凸轮机构的双柱塞砂浆泵的工作凸轮机构和补偿凸轮机构进行运动学分析,建立了砂浆泵运动机构的仿真模型.用Matlab软件进行了仿真分析,进一步验证了运动学分析模型的正确性. 相似文献
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