摘要：Aimed at two typical composite floor systems of through steel bridges in high speed railway,design methods of headed studs were put forward for different composite members through comparing and analyzing the structure,mechanical characteristics and transmission routes of deck *** simplified calculation models were brought out for the stud design of the longitudinal girders and transverse girders in the composite floor system of Nanjing Dashengguan Yangtze River Bridge (NDB).Studs were designed and arranged by taking the middle panel of 336 m main span for *** results show that under deck loads,the longitudinal girders in the composite floor system of through steel bridges are in tension-bending state,longitudinal shear force on the interface is caused by both longitudinal force of "The first mechanical system" and vertical bending of "The second mechanical system",and studs can be arranged with equal space in terms of the shear force in range of 0.2d (where d is the panel length) on the top *** girders in steel longitudinal and transverse girders-concrete slab composite deck are in compound-bending state,and out-of-plane bending has to be taken into account in the stud *** orthotropic integral steel deck-concrete slab composite deck,out-of-plane bending of transverse girders is very small so that it can be neglected,and studs on the orthotropic integral steel deck can be arranged according to the structural *** above design methods and simplified calculation models have been applied in the stud design of NDB.

摘要：Current design method for circular sliding slopes is not so reasonable that it often results in slope (sliding.) As a result, artificial neural network (ANN) is used to establish an artificial neural network based inverse design method for circular sliding slopes. A sample set containing 21 successful circular sliding slopes excavated in the past is used to train the network. A test sample of 3 successful circular sliding slopes excavated in the past is used to test the trained network. The test results show that the ANN based inverse design method is valid and can be applied to the design of circular sliding slopes.

摘要：To better remove the contamination on the surface of a heat-exchanger in urban sewage source heat pump system （USSHPS）, this paper analyzes the feasibility of strong self-flushing on the basis of experiments and presents a new on-line self-flushing technique, which alternately flushes part of heat transfer tubes. In addition, operation principles and the structure of the new heat-exchanger are introduced and the feasible economi- cal and technological cleaning plans are given by design calculation and scheme comparison. The result shows that keeping each tube washed for one minute with 5 m/s, the operating cost is lower than ￥5 and when one flushing pump ahemately flushes 10-20 heat exchangers, the saved costs of flushing 10 tubes alternately are over 4 times of the increased costs.

摘要：Turpan traditional residences are primitive green buildings adaptive to the climate, materials and geographical conditions of the arid regions. The environmental adaptability of local residences and the construction methods was elaborated to provide references for building new oasis settlements in the local area.

摘要：This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou *** decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main *** measures are used to decrease noncoincident centers of mass and *** subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning *** from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending *** attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive *** observations after completion construction indicate that the building as well as the proposed design measures work well.

摘要：A rotating axisymmetric circular nanoplate is modeled by the Mindlin plate *** Mindlin plate theory incorporates the nonlocal scale and strain gradient *** shear deformation of the circular nanoplate is considered and the nonlocal strain gradient theory is utilized to derive the governing differential equation of motion that describes the out-of-plane free vibration behaviors of the *** differential quadrature method is used to solve the governing equation numerically,and the natural frequencies of the out-of-plane vibration of rotating nanoplates are obtained *** kinds of boundary conditions are commonly used in practical engineering,namely the fixed and simply supported constraints,and are considered in numerical *** variations of natural frequencies with respect to the thickness to radius ratio,the angular velocity,the nonlocal characteristic scale and the material characteristic scale are analyzed in *** particular,the critical angular velocity that measures whether the rotating circular nanoplate is stable or not is obtained *** presented study has reference significance for the dynamic design and control of rotating circular nanostructures in current nano-technologies and nano-devices.

摘要：In this study, two full-size concrete wails were tested and analyzed to demonstrate the effectiveness of a chemically reactive enamel （CRE） coating in improving their mechanical behavior under blast loading： one with CRE-coated rebar and the other with uncoated rebar. Each wall was subjected in sequence to four explosive loads with equivalent 2, 4, 6-trinitrotoluene （TNT） charge weights of 1.82, 4.54, 13.6, and 20.4 kg. A finite element model of each wall under a close-in blast load was developed and validated with pressure and strain measurements, and used to predict rebar stresses and concrete surface sWain distributions of the wall. The test results and visual inspections consistently indicated that, compared with the barrier wall with uncoated reinforcement, the wall with CRE-coated rebar has fewer concrete cracks on the front and back faces, more effective stress transfers from concrete to steel rebar, and stronger connections with its concrete base. The concrete surface strain distributions predicted by the model under various loading conditions are in good agreement with the crack patterns observed during the tests.

摘要：目的:活性瓷釉涂层能够显著增强钢筋的防腐蚀能力,同时明显提升钢筋与混凝土的粘结力。通过对活性瓷釉涂层钢筋以及钢纤维增强混凝土板在动、静力荷载作用下的承载力、变形特性以及破坏特征的研究,为活性瓷釉涂层技术在钢筋混凝土结构中的应用奠定理论基础。创新点:1.对活性瓷釉涂层钢筋混凝土板的动、静力学性能进行系统研究;2.探究活性瓷釉钢纤维在混凝土结构中的作用机理。方法:1.通过对活性瓷釉涂层钢筋混凝土板进行爆炸实验(图3),揭示活性瓷釉涂层钢筋混凝土结构的动力破坏特征(图5和6);2.通过对活性瓷釉涂层钢筋混凝土板进行静力实验(图4),研究在"点"荷载和"线"荷载作用下混凝土板的力学性能;3.通过分析钢纤维在钢筋混凝土结构中的传力机理,提出活性瓷釉涂层钢纤维在钢筋混凝土结构中的设计方法(图13)。结论:1.活性瓷釉涂层能够显著改善钢筋在混凝土结构中的传力性能;在动力荷载作用下,涂层钢筋混凝土结构的破坏程度明显减轻。2.活性瓷釉涂层能够显著改善钢筋混凝土结构的变形特性,大大增强其耗能能力。3.采用活性瓷釉涂层的钢纤维,其纤维长度可适当减小。

摘要：Recent efforts have focused on the fabrication and application of three- dimensional （3-D） nanoarchitecture electrodes, which can exhibit excellent electrochemical performance. Herein, a novel strategy towards the design and synthesis of size- and thickness-tunable two-dimensional （2-D） MnO2 nanosheets on highly conductive one-dimensional （l-D） backbone arrays has been developed via a facile, one-step enhanced chemical bath deposition （ECBD） method at a low temperature （-50 ℃）. Inclusion of an oxidizing agent, BrO3-, in the solution was crucial in controlling the heterogeneous nucleation and growth of the nanosheets, and in inducing the formation of the tailored and uniformly arranged nanosheet arrays. We fabricated supercapacitor devices based on 3-D MnO2 nanosheets with conductive Sb-doped SnO2 nanobelts as the backbone. They achieved a specific capacitance of 162 F·g-1 at an extremely high current density of 20 A·g% and good cycling stability that shows a capacitance retention of -92% of its initial value, along with a coulombic efficiency of almost 100% after 5,000 cycles in an aqueous solution of I M Na2SO4. The results were attributed to the unique hierarchical structures, which provided a short diffusion path of electrolyte ions by means of the 2-D sheets and direct electrical connections to the current collector by 1-D arrays as well as the prevention of aggregation by virtue of the well-aligned 3-D structure.

摘要：An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a *** catalyst with Pt content as low as 0.2 wt%exhibits high activities,chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of *** conversion of nitrobenzene can reach 3170 molconv h^–1 molPt^–1 under mild conditions(30°C,5 bar),which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction *** spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity,which decreases the contact possibility between the reducible groups of nitroarenes and Pt *** unique surface properties ofα-Fe2O3 play an important role in the reaction *** provides active sites for hydrogen spillover and reactant adsorption,and ultimately completes the hydrogenation of the nitro group on the catalyst surface.