摘要：Both reverse osmosis(RO) and nanofiltration(NF) membranes have been increasingly used for water purification and desalination. However, the salt rejection of NF membranes is quite different from that of RO membranes,which makes a significant distinction in their process designs. This work started from the performance investigation of a single NF membrane element and then focused on the process design of the NF system for surface water treatment. In experimental tests, it was found that the observed rejection of the NF element becomes nearly constant when the concentrate flow is large enough, while the membrane flux of the NF element is quite stable regardless of the water flow across the membrane surface. These findings can be used to instruct the process design of the NF system for surface water treatment. In process design, a two-stage arrangement is sufficient for the NF system to reach the highest water recovery, while the RO system requires a three-stage arrangement.

摘要：The inlet attack angle of rotor blade reasonably can be adjusted with the change of the stagger angle of inlet guide vane (IGV); so the efficiency of each condition will be affected. For the purpose to improve the efficiency, the DSP (Digital Signal Processor) controller is designed to adjust the stagger angle of IGV automatically in order to optimize the efficiency at any operating condition. The A/D signal collection includes inlet static pressure, outlet static pressure, outlet total pressure, rotor speed and torque signal, the efficiency can be calculated in the DSP, and the angle signal for the stepping motor which control the IGV will be sent out from the D/A. Experimental investigations are performed in a three-stage, low-speed axial compressor with variable inlet guide vanes. It is demonstrated that the DSP designed can well adjust the stagger angle of IGV online, the efficiency under different conditions can be optimized. This establishment of DSP online adjustment scheme may provide a practical solution for improving performance of multi-stage axial flow compressor when its operating condition is varied.

摘要：近年来,纳米尺度上范德华材料中声子极化激元的研究因在纳米光子学中的潜在应用而受到广泛关注.这些材料具有亚衍射分辨成像和传感的独特能力,因而成为纳米光子学领域新技术开发的热门途径.尽管声子极化激元材料的研究取得了很多进展,但由于这些材料的绝缘特性,其在实现声子极化激元的动态可逆操纵方面仍然存在挑战.最新研究发现,借助VO_(2)薄膜,可以实现α-MoO_(3)中各向异性声子极化激元的可逆操纵.VO_(2)薄膜是一种近室温相变材料,因其相变前后绝缘态和金属态之间介电性能的巨大变化受到广泛关注.最新的一项研究展示了精心构建的α-MoO_(3)/VO_(2)异质结构,改变温度调控VO_(2)薄膜的介电性能,能够调谐中红外波段极化激元的传播.这些结果展示了一种在纳米尺度上控制光能流动的有效方法,并为集成平面亚衍射激元器件的设计和制造提供了指导.

摘要：Most transmission gratings in the x-ray region work with their first orders and dispersion is limited by the line density achievable with current fabrication technology. We present a novel design of a two-dimensional x-ray transmission grating. The grating works with higher dispersion using its second orders, and the influence from first and third orders can be suppressed. A grating according to the novel design is fabricated and its diffraction performance is tested in comparison with a traditional x-ray transmission grating with the same line density. The novel grating could be especially useful when high dispersion is desired while the fabrication of high-density gratings becomes more difficult.

摘要：Dunhuang murals are gems of Chinese traditional art. This paper demonstrates a simple, yet powerful method to automatically identify the aesthetic visual style that lies in Dunhuang murals. Based on the art knowledge on Dunhuang murals, the method explicitly predicts some of possible image attributes that a human might use to understand the aesthetic visual style of a mural. These cues fall into three broad types: ① composition attributes related to mural layout or configuration; ② color attributes related to color types depicted; ③ brightness attributes related to bright conditions. We show that a classifier trained on these attributes can provide an efficient way to predict the aesthetic visual style of Dunhuang murals.

摘要：Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented for its proactive remanufacturing with setting up to explore the best remanufacturing time point in this *** a certain model of long distance pipeline compressor impeller with the Basquin equation and the design method of impeller,the mathematical relationship between the changes of structure and life of the impeller was *** the service mapping model between the structure and life was set up and simulated by ANSYS ***,the service mapping model was applied to feedback the original design for proactive *** this work,the best proactive remanufacturing time point of impeller was analyzed with the service mapping model,and the structural parameter values could be optimized at this time ***,in the results of this simulation,it proves that the impeller under this optimization performance could satisfy the impeller operating ***,comparing with the traditional optimization design method,the remanufacturing optimized design based on the service mapping model is feasible in proactive remanufacturing for sustainable development.

摘要：玻璃表面微纳结构的设计和制造在实现所需功能方面具有重要意义.然而,玻璃固有的硬度和脆性给传统制造方法带来了不便.因此,开发一种简单且可控的制造策略对于制备具备功能应用的微纳结构玻璃至关重要.在本文中,我们提出了一种创新方法,利用可溶性氯化钠颗粒作为前驱体模板,在玻璃表面上创建可定制的多孔结构.通过我们的先导成型策略,成功利用可溶性氯化钠颗粒的潜力作为前驱体模板,从而便于制造量身定制的多孔玻璃表面.通过调节这些颗粒的大小和组合,我们实现了对所得多孔玻璃的连续调控,范围从超亲水(1°)到超疏水(142°).值得注意的是,制备的多孔玻璃表面表现出显著的亲油性,展示了在油水分离和自清洁等多种应用方面的巨大潜力.最重要的是,即使经过了10次制造迭代,玻璃表面的疏水-亲油功能依然完好,凸显了我们策略的耐久性和可重复性.这种方法为实现玻璃的特殊功能提供了方便且具有成本效益的途径,为不同领域的进展铺平了道路.

摘要：探索具有深紫外相位匹配能力的新型非线性光学材料是当前研究热点.本文从硼氧阴离子框架出发,发现由π共轭BO_(3)基团组成一维(BO_(2))∞链的电子离域导致了极化特性增强,可实现非线性光学性能的优化.据此,本文预测了以(BO_(2))∞链为阴离子框架的CaBO_(2)F体系.重点研究了三种能量最低的结构CaBO_(2)F-Ⅰ,CaBO_(2)F-Ⅱ和CaBO_(2)F-Ⅲ,设计了热力学上可进行的反应路径.第一原理计算表明,CaBO_(2)F-Ⅰ,CaBO_(2)-F-Ⅱ和CaBO_(2)F-Ⅲ具有较宽的带隙,合适的双折射(0.076–0.108@1064 nm)和较大的倍频系数(2.1–2.7×KDP).其中,计算得到CaBO_(2)F-Ⅰ的最短相位匹配波长在约为195 nm(基于HSE06带隙修正剪刀算符),证明了含有定向电子离域的(BO_(2))∞链是深紫外非线性光学材料的潜在阴离子框架.本文通过将机理研究与验证性的结构预测相结合实现了自上而下设计深紫外非线性光学结构模板,该研究为探索新型非线性光学材料提供了新的策略.

摘要：由于油资源的缺乏供应，为其他的基于煤的燃料的过程， dimethylether (DME ) ，在化学工程作为一个重要过程出现了地。与关于 DME 合成和分离的实验室实验数据，当在从 syngas 的泥浆床反应堆的 DME 的一步舞合成被采用时，为有高纯净的 DME 的生产进程被建议。根据试验性的研究和过程分析，为模拟过程的合适的单位模块和 thermophysical 计算方法被选择。合并了反应的试验性地坚定的参数为 DME 合成的动态模型，在非随机的二液体的方程(NRTL ) 的参数的回归常数与内建的性质模型，一起在 DMEseparation 系统为二进制部件当模特儿进程程序表在白杨正平台上被开发并且模仿。模拟结果与一致很好，数据在实验室实验获得了。因此，精确模拟结果把有用参考书提供给类似的设备设计和过程操作优化。

摘要：Co87Nb10Zr3,Co76Nb19Zr5,Co64Nb26Zr10 and Co64Nb16Zr20 amorphous films were deposited on noncrystalline glass substrates by DC unbalanced magnetron sputtering. The compositions of amorphous films were tailored in the light of the individual deposition rate of Co,Nb and Zr. The amorphous films with the anticipated composition were prepared by means of co-sputtering Co,Nb and Zr targets simultaneously. It is indicated that there is interaction among three targets during co-sputtering. The morphology and composition of the films were observed by SEM,AFM and EDS. The structure and magnetic property were measured by XRD and physical property measurement system(PPMS) . The coercivity changes with the composition,varying from 240 to 1 600 A/m. After vacuum isothermal annealing at temperatures of 475,500,525 and 550 ℃ for 15 and 30 min,respectively,it is found that high Nb content is beneficial to improving thermal stability of amorphous films. The crystallized films have the mean grain size of 2-19 nm.