Taking the realization of goods in commodity arrangement design as the primary coverage,it analyzed in realization of goods to arrange the design the connotation and the significance.It analyzed the marketing model in the realization of goods design function,as well as in arrangement design commodity arrangement and connection arrangement design.It elaborated the commodity arrangement design in the influence brand image transmission aspect factor,proposed the commodity arrangement design would have the vital role to the brand image's transmission aspect,it would be in the brand image recognition and the promoted process the essential important component.
Starting from the creation of civil auspicious words,it discussed the application of impact several factors.It analyzed the base and content of visual representation in the creation of civil auspicious words,summed up the civil word creative thinking by many factors.Through the analysis of typical works,it expounded the close link between creating ideas and works of folk forms,as reflecting in the lasting effects of folk custom activity on the creative,reflected the profound impact of real life and ideal on the creation of civil words,and also manifested themselves in society caused by the civil concept of text patterns and the diversity of performance.It pointed out the rich folk text behind the creation of folk culture has a deep soil,the text of the creation of civil and private lifestyle and behavior norms,and culture are closely linked.
The motion of the floating platform is one of the important factors influencing the safety of testing string. The allowable motion limits of various floating drilling platforms are discussed and their calculation formulas are presented, based on which the nonlinear dynamic response characteristics of the testing tube are investigated through ABAQUS software. Results show that an excessive offset of floating platform will cause many problems to testing tube, such as operation difficulty in rising and landing pipe string, disconnection difficulty of testing tree in case of emergency. Under heave motion and slow drift motion condition, the maximum Mises stress appears in the part closed to the upper end. The heave and horizontal motions of the platform have a superposition influence on the axial force of the pipe. So, a more precise dynamic theoretical model should be developed to study the longitudinal-transverse coupled vibration of testing string in the future.
An efficient electro-oxidative C–H/N–H activation with 1,3-diynes has been achieved with a robust earth-abundant cobalt catalyst. The electrochemical C–H functionalization was accomplished with ample scope and remarkable functional group compatibility in a simple undivided cell. This protocol avoids the utilization of stoichiometric and cost-intensive chemical oxidants in C–H activation, thus forming hydrogen as the only byproduct.
Marine risers typically experience nonlinear vibration failure problems caused by the ocean vortex excitation force. To resolve this, the Hamilton variational principle is applied to establish a vortex-induced vibration (VIV) model for a flexible riser. A wake oscillator model is employed to simulate the vortex-induced forces of cross flow (CF) and inline flow (IL) and their coupling, considering the effect of top tension and internal flow on the riser. The VIV model is solved by combining the Newmark–β and Runge–Kutta methods and then verified by comparing the calculation results of the proposed vibration model with data in published literature. Based on the foregoing, the effects of uniform flow, top tension, and shear flow on the VIV behaviour of risers with a large aspect ratio are systematically investigated. Moreover, the VIV characteristics are identified. First, the results demonstrate that, when the top tension is 10 t, the IL vibration is 0.73 Hz and the CF vibration is 0.36 Hz, which shows that the IL vibration is twice as high as the CF vibration. Moreover, the amplitude of the latter is between 7 and 21 times that of the former, which are respectively 0.018 and 0.12 m. Second, the shear velocity and top tension also have considerable influence on the IL vibration under shear flow. Third, the CF vibration has a frequency-locking effect under shear flow and uniform flow conditions. The IL vibration exhibits a frequency-locking effect under uniform flow and a multifrequency effect under shear flow. The study led to the formulation of a theoretical method for safety evaluation and a practical approach for effectively improving the service life of marine risers.
Abstract In deep-water test conditions, the riser-test pipe system (RTS) is subject to the vortex induced effect on riser, flow induced effect on test pipe and longitudinal/transverse coupling effect, which is prone to buckling deformation, fatigue fracture and friction perforation. To resolve this, the three-dimensional (3D) nonlinear vibration model of deep-water RTS is established using the micro-finite method, energy method and Hamilton variational principle. Based on the elastic-plastic contact collision theory, the nonlinear contact load calculation method between riser and test pipe is proposed. Compared with experimental measurement results, calculation results of the proposed vibration model in this study and the single tubing vibration model in our recent work, the correctness and effectiveness of the proposed vibration model of the deep-water RTS are verified. Meanwhile, the cumulative damage theory is used to establish the fatigue life prediction method of test pipe. Based on that, the influences of outflow velocity, internal flow velocity, significant wave height, as well as top tension coefficient on the fatigue life of test pipe are systematically analyzed. The results demonstrate that, first, with the increase of outflow velocity, the maximum alternating stress, the annual fatigue damage rate increased and the service life decreased significantly. The locations where fatigue failure of the test tube is easy to occur are mainly distributed at the upper “one third” and the bottom of test pipe. Second, with the increase of internal flow velocity, the “one third effect” of the test pipe will decrease, and is shown “the bottom damage effect”, which needs the attention of field operators. Third, during field operation, it is necessary to properly configure the top tension coefficient so that there can be a certain relaxation between the riser and the test pipe, so as to cause transverse vibration and consume some axial energy and load. The study led to the formulation of a theoretical method for safety evaluation and a practical approach for effectively improving the fatigue life of deep-water test pipe.
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