欧华降价30％：中国车载影音行业蜕变的分水岭

兵法有云：谋定而后动。欧华电子有限公司总经理徐应龙先生强调．这次大规模的降价行动，一个很重要的目的是让行业的经销商、批发商、零售商了解产品真正的利润空间，促进实现合理的利润分割，实现行业操作的规范化，进而促进车载影音产品的普及和行业的健康发展。     

一种适应长效保洁的小型水葫芦机械清理装置的设计

近年福建省水葫芦危害严重。在调研省内与国内水葫芦机械治理的类型、成功经验的基础上。推荐设计一种小型水葫芦机械清理装置,主机集切断、打捞、适度脱水、储存（2—3吨）与输送功能。主机装置包含切割机构、输送机构、挤压机构;船体采用框架铁皮结构、平底和安全平衡翼结构。适用于较浅的中小型河道、水库区域的长效保洁。具有设备造价低,打捞成本低。连续作业效率高（密生5—7吨／h,散生4000m^2水域／h）的特点。     

Fe@C@Gd2O3:Eu magnetic-fluorescent composites: Facile synthesis,structure and properties

In this study, the bifunctional Fe@C@Gd₂O₃:Eu³⁺ composites were prepared via a simple co-precipitation progress followed by a subsequent heat treatment under N₂ atmosphere. The reactive carbon interlayer offers many advantages including separating photoluminescent material from magnetic material and reducing magnetite Fe₃O₄ to metal Fe. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM) and photoluminescence spectroscopy (PL) were used to analyze the structure, morphology, magnetic and luminescence properties of the composites. The Fe@C@Gd₂O₃:Eu³⁺ composites with well-crystallized and core–shell structure were prepared and displayed good ferrimagnetic behavior at room temperature and a strong red emission. In addition, due to the excellent magnetic and luminescence properties of the prepared composites, they may have many great potential applications in many fields, such as biological imaging, cell tracking and drug delivery.     

Effect of contact thermal resistance on temperature distributions of concrete-filled steel tubes in fire

To predicate the temperature distribution of concrete-filled steel tubes(CFSTs) being exposure to fire,a finite element analysis model was developed using a finite element package,ANSYS.A suggested value of contact thermal resistance was therefore proposed with the supporting of massive numbers of collected test data.Parametric analysis was conducted subsequently towards the cross-sectional temperature distribution of CFST columns in four-side fire,in which the exposure time,width of the cross section,steel ratio were taken into account with considering contact thermal resistance.It was found that contact thermal resistance has little effect on the overall temperature regulation with the exposure time,the width of cross-section or the change of steel ratio.However,great temperature dropping at the concrete adjacent to the contact interface,and gentle temperature increase at steel tube,exist if considering contact thermal resistance.The results of the study are expected to provide theoretical basis for the fire resistance behavior and design of the CFST columns being exposure to fire.     

TWO-DIMENSIONAL PARTICLE IMAGE VELOCIMETRY（PIV） MEASUREMENTS IN A TRANSPARENT CENTRIFUGAL PUMP

A special transparent centrifugal pump is designed. Detailed optical measurements of the flow inside the rotating passages of a five-bladed shroud centrifugal pump impeller have been performed by using two-dimensional particle image velocimetry (PIV). The flow is surveyed at three load conditions qV/Vd = 0.4, qV/qVd = 1.0, qVlqVd = 1.5, respectively. As a result, phase averaged PIV velocity vector maps on three planes between hub and shroud of the impeller are presented. At design load, the mean field of relative velocity is predominantly vane congruent, showing well-behaved flow without separation. The distributions of the relative velocity on different plane along the pump shaft are very different and there is always a low velocity zone near the pressure-side of the blade at both low and design flow rate, but the low-velocity-zone at the low flow rate is much larger than that at the design one. The study demonstrates that the PIV technique is efficient in providing reliable and detailed velocity data o     

地源热泵在空调中应用的探讨

本文介绍了地源热泵的特点、工作原理和分类，分析了地源热泵的关键技术，并与相关的热泵技术进行了性能比较，对地源热泵进行了技术经济分析，最后还介绍了地源热泵技术在制冷空调中的广阔应用前景。     

复合加固法在桥梁临时加固中的应用

以长寿—开县沿线的齐心桥加固为例,介绍了同时采用粘贴钢板法和喷射钢纤维混凝土的复合加固法对桥梁进行加固的计算过程和施工工艺,说明了粘贴钢板和喷射钢纤维混凝土在桥梁临时加固中的适用性和有效性。