高效节能热泵错流多效蒸发复杂系统

为了大幅降低错流多效蒸发过程的能耗,首次将蒸汽喷射式热泵技术、冷凝水闪蒸和溶液闪蒸等3种节能措施同时运用到错流多效蒸发系统中,并建立了用矩阵方程描述的该系统的数学模型。模型具有很强的通用性,可实现热泵在任意效抽汽的功能,可简化为只有其中若干种节能措施组合或无上述节能措施的错流、并流、逆流多效蒸发系统的模型。在满足约束条件的前提下,模型存在最佳的热泵喷射系数和抽汽位置,同时采用上述3种节能措施且在最佳条件下模型是高效节能的。浓缩氢氧化钠溶液的热泵错流五效蒸发系统的模拟结果表明,当热泵的喷射系数为0.15、抽汽位置在第2效,采用冷凝水闪蒸和溶液闪蒸时系统节省的生蒸汽消耗量高达32.51%。     

Tri-view morphing

This paper presents an efficient image-based approach to navigate a scene based on only three wide-baseline uncalibrated images without the explicit use of a 3D model. After automatically recovering corresponding points between each pair of images, an accurate trifocal plane is extracted from the trifocal tensor of these three images. Next, based on a small number of feature marks using a friendly GUI, the correct dense disparity maps are obtained by using our trinocular-stereo algorithm. Employing the barycentric warping scheme with the computed disparity, we can generate an arbitrary novel view within a triangle spanned by three camera centers. Furthermore, after self-calibration of the cameras, 3D objects can be correctly augmented into the virtual environment synthesized by the tri-view morphing algorithm. Three applications of the tri-view morphing algorithm are demonstrated. The first one is 4D video synthesis, which can be used to fill in the gap between a few sparsely located video cameras to synthetically generate a video from a virtual moving camera. This synthetic camera can be used to view the dynamic scene from a novel view instead of the original static camera views. The second application is multiple view morphing, where we can seamlessly fly through the scene over a 2D space constructed by more than three cameras. The last one is dynamic scene synthesis using three still images, where several rigid objects may move in any orientation or direction. After segmenting three reference frames into several layers, the novel views in the dynamic scene can be generated by applying our algorithm. Finally, the experiments are presented to illustrate that a series of photo-realistic virtual views can be generated to fly through a virtual environment covered by several static cameras.     

覆冰接触网的有限元仿真及其小比例模型试验

为了为接触网覆冰的在线监测提供理论基础,对覆冰后接触网的静态响应进行研究。首先,利用ANSYS建立6跨张力自动补偿的简单链型悬挂接触网的有限元模型,对不同覆冰厚度时的接触网的静态响应进行仿真分析,得到随覆冰厚度的变化的接触线和承力索的弛度变化以及下锚处位移。然后,基于相似理论建立1/50的6跨接触网小比例模型。通过模型试验得到不同厚度下接触线和承力索的下锚处位移,对比小比例模型的仿真和试验结果验证了小比例模型的可用性。将模型试验结果推广到实际接触网,对比推广后的试验结果和实际接触网的仿真结果,进一步验证了小比例模型的正确性。该小比例模型可为深入研究接触网特性试验提供试验基础。     

超高分子量聚乙烯纤维用树脂性能与纺丝研究

超高分子量聚乙烯(UHMWPE)具有许多卓越的性能,被广泛地应用于工业及一些特殊领域.研究了UH-MWPE树脂的性能,并进行UHMWPE的纺丝试验,发现不同厂家的纺丝用UHMWPE树脂在性能上存在一定差异,而且树脂性能的差异对纤维力学性能造成一定影响.     

电力网络在线仿真系统的矢量流追踪算法

为解决大规模电力网络在线仿真系统中邻接矩阵阶数过大导致计算机运算困难的问题,提出了一种实时仿真的矢量流追踪实用算法。在实时数据融合模型和SVG矢量发布格式扩展的基础上,定义了拓扑矢量流图,构造了拓扑矢量的属性域模型,并设计了拓扑矢量流图追踪算法的流程。对H桥形拓扑矢量流图的计算逻辑表达式优化和具体追踪计算,使得优化后的计算效率提高了40%;采用所提算法对算例网络进行馈线停电在线仿真,计算正确率达到100%,表明所提算法能满足电力监控系统的在线仿真应用要求。     

铁路接触网棘轮补偿器性能的在线监测

传动效率是评价棘轮补偿器性能的一个重要参数,实时监测传动效率的变化可以用于评价棘轮补偿器的性能。为了分析传动效率的变化规律,以目前高速铁路广泛使用的棘轮补偿器为原型,利用ANSYS建立了棘轮补偿器的刚柔耦合仿真模型,运用该模型进行了棘轮补偿器的静动态仿真;理论分析得到了补偿绳的张力分布,和静态仿真的结果进行对比,两者相差很小,验证了仿真模型的正确性;仿真分析了动态荷载作用下棘轮补偿器传动效率的变化规律,和理论分析得到的规律进行对比,两者较为符合;分析卡滞程度不同时传递效率的变化,卡滞越严重传递效率的变化率越小;提出了一种棘轮补偿器传动效率的在线监测方法,在津秦客运专线上进行了现场测试,通过分析采集得到的数据,对棘轮补偿器性能的进行了评估。     

High Quality Perovskite Crystals for Efficient Film Photodetectors Induced by Hydrolytic Insulating Oxide Substrates

A high quality perovskite film is a key factor in determining the device performance, such as photovoltaic cells, light‐emission diodes, lasers, and photodetectors. Here, a method is presented to improve the crystalline quality of perovskite films on surface‐oxygen‐rich insulating oxide substrates, which can promote the growth of both the polycrystalline and single crystals and enhance the adhesion between the perovskites and the substrates. A much longer carrier diffusion length of exceeding 5 µm together with significantly reduced trap density and nonradiative recombination is achieved for the film. These perovskite films show much better lasing and photodetector performance, indicating promising applications for the light emitting, lasing, and detector devices.     

Methylammonium cation deficient surface for enhanced binding stability at TiO<Subscript>2</Subscript>/CH<Subscript>3</Subscript>NH<Subscript>3</Subscript>PbI<Subscript>3</Subscript> interface

Heterojunction interfaces in perovskite solar cells play an important role in enhancing their photoelectric properties and stability.Till date,the precise lattice arrangement at TiO2/CH3NH3PbI3 heterojunction interfaces has not been investigated clearly.Here,we examined a TiO2/CH3NH3PbI3 interface and found that a heavy atomic layer exists in such interfaces,which is attributed to the vacancies of methylammonium (MA) cation groups.Further,first-principles calculation results suggested that an MA cation-deficient surface structure is beneficial for a strong heterogeneous binding between TiO2 and CH3NH3PbI3 to enhance the interface stability.Our research is helpful for further understanding the detailed interface atom arrangements and provides references for interfacial modification in perovskite solar cells.     

A Simple Way to Simultaneously Release the Interface Stress and Realize the Inner Encapsulation for Highly Efficient and Stable Perovskite Solar Cells

The mixed halide perovskites have become famous for their outstanding photoelectric conversion efficiency among new‐generation solar cells. Unfortunately, for perovskites, little effort is focused on stress engineering, which should be emphasized for highly efficient solar cells like GaAs. Herein, polystyrene (PS) is introduced into the perovskite solar cells as the buffer layer between the SnO₂ and perovskite, which can release the residual stress in the perovskite during annealing because of its low glass transition temperature. The stress‐free perovskite has less recombination, larger lattices, and a lower ion migration tendency, which significantly improves the cell's efficiency and device stability. Furthermore, the so‐called inner‐encapsulated perovskite solar cells are fabricated with another PS capping layer on the top of perovskite. As high as a 21.89% photoelectric conversion efficiency (PCE) with a steady‐state PCE of 21.5% is achieved, suggesting that the stress‐free cell can retain almost 97% of its initial efficiency after 5 days of “day cycle” stability testing.     

遥控起爆器的汉明码纠错应用研究

(8,4)汉明码易于遥控起爆器实现纠错功能,文章给出了其编译码算法,并采用CC1100无线模块对其性能进行了测试。测试结果表明,采用(8,4)汉明码,误码率最大降低了80%,遥控距离最大增加了近50%。(8,4)汉明码能有效降低遥控起爆的误码率,增加遥控距离,在遥控起爆器中具有很强的实用价值。