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131.
为了解空巢青年对住宅空间的需求,为其提供更舒适的住宅环境,文章通过问卷法,结合IBM SPSS Statistics25 软件对获得数据进行因子分析(主成分分析),并在后期借助Censydiam 模型进行需求分析, 得到空巢青年对住宅的空间构成需求和家具选择需求,提出三条空间设计策略.同时为空巢青年住宅空间设计提供思考和借鉴. 相似文献
132.
Herein, this paper reports a facile method to prepare electrospun carbon nanofiber mats (ECNFMs) with high specific surface area and interconnected structure using polyacrylonitrile (PAN) as a precursor and novolac resin (NOC) as a polymer sacrificial pore-making agent. Without additional treatment, the prepared ECNFMs have a highly porous structure because NOC decomposes in a wider temperature range than most polymer activators. The NOC content in the PAN nanofibers shows important effects on porosity. The BET specific surface area of ECNFMs reaches a maximum of 1468 m2 g−1 when the precursor nanofibers contained 30 wt% NOC (ECNFM-3) after carbonization at 1000 °C. The supercapacitor device from ECNFM-3 electrode and all-solid-state electrolyte shows excellent cycling durability and high specific capacitance: ≈99.72% capacitance retention after 10 000 charge/discharge cycles and ≈320 mF cm−2 at 0.25 mA cm−2. Furthermore, it shows a large energy density of ≈11.1 Wh cm−2 under the power density of 500 mW m−2. Activation of carbon nanofibers simply by the addition of NOC into precursor nanofibers can offer a handy way to prepare ECNFMs for high-performance all-solid-state supercapacitors and other potential applications. 相似文献
133.
Maikel León Lusine Mkrtchyan Benoît Depaire Da Ruan Koen Vanhoof 《Knowledge and Information Systems》2014,39(2):435-462
In modern society, more and more attention is given to the increase in public transportation or bike use. In this regard, one of the most important issues is to find and analyse the factors influencing car dependency and the attitudes of people in terms of preferred transport mode. Although the individuals’ transport behavioural modelling is a complex task, it has a notable social and economic impact. Thus, in this paper, fuzzy cognitive maps are explored to represent the behaviour and operation of such complex systems. This soft-computing technique allows modelling how the travellers make decisions based on their knowledge of different transport modes properties at different levels of abstraction. These levels correspond to the hierarchy perception including different scenarios of travelling, different benefits of choosing a specific travel mode, and different situations and attributes related to those benefits. We use learning and clustering of fuzzy cognitive maps to describe travellers’ behaviour and change trends in different abstraction levels. Cluster estimations are done before and after the learning of the maps, in order to compare people’s way of thinking if only considering an initial view of a transport mode decision for a daily activity, and when they really have a deeper reasoning process in view of benefits and consequences. The results of this study will help transportation policy decision makers in better understanding of people’s needs and consequently will help them actualizing different policy formulations and implementations. 相似文献
134.
Properties and Printability of Inkjet and Screen-Printed Silver Patterns for RFID Antennas 总被引:2,自引:0,他引:2
José F. Salmerón Francisco Molina-Lopez Danick Briand Jason J. Ruan Almudena Rivadeneyra Miguel A. Carvajal L. F. Capitán-Vallvey Nico F. de Rooij Alberto J. Palma 《Journal of Electronic Materials》2014,43(2):604-617
We report the modeling, and geometrical and electrical characterization, of inkjet and screen-printed patterns on different polymeric substrates for use as antennas in radio-frequency identification (RFID) applications. We compared the physical and electrical characteristics of two silver nanoparticle-based commercial inkjet-printable inks and one screen-printable silver paste, when deposited on polyimide (PI), polyethylene terephthalate (PET), and polyetherimide (PEI) substrates. First, the thickness of the inkjet-printed patterns was predicted by use of an analytical model based on printing conditions and ink composition. The predicted thickness was confirmed experimentally, and geometrical characterization of the lines was completed by measuring the root-mean-square roughness of the patterns. Second, direct-current electrical characterization was performed to identify the printing conditions yielding the lowest resistivity and sheet resistance. The minimum resistivity for the inkjet-printing method was 8.6 ± 0.8 μΩ cm, obtained by printing four stacked layers of one of the commercial inks on PEI, whereas minimum resistivity of 44 ± 7 μΩ cm and 39 ± 4 μΩ cm were obtained for a single layer of screen-printed ink on polyimide (PI) with 140 threads/cm mesh and 90 threads/cm mesh, respectively. In every case, these minimum values of resistivity were obtained for the largest tested thickness. Coplanar waveguide transmission lines were then designed and characterized to analyze the radio-frequency (RF) performance of the printed patterns; minimum transmission losses of 0.0022 ± 0.0012 dB/mm and 0.0016 ± 0.0012 dB/mm measured at 13.56 MHz, in the high-frequency (HF) band, were achieved by inkjet printing on PEI and screen printing on PI, respectively. At 868 MHz, in the ultra-high-frequency band, the minimum values of transmission loss were 0.0130 ± 0.0014 dB/mm for inkjet printing on PEI and 0.0100 ± 0.0014 dB/mm for screen printing on PI. Although the resistivity achieved is lower for inkjet printing than for screen printing, RF losses for inkjetted patterns were larger than for screen-printed patterns, because thicker layers were obtained by screen printing. Finally, several coil inductors for the HF band were also fabricated by use of both printing techniques, and were used as antennas for semi-passive smart RFID tags on plastic foil capable of measuring temperature and humidity. 相似文献
135.
Shi-yun Wu Xiao-yu Wu Bin Xu Rong Cheng Feng Luo Shuang-chen Ruan 《Journal of Materials Processing Technology》2014,214(11):2668-2675
The Sn–Bi eutectic alloy powder in the micro-cavity was melted by ultrasonic vibration and rapidly cooled to form micro parts; no subsequent sintering process was required. Three kinds of Sn–Bi alloy micro gears were successfully fabricated, which verified the feasibility of the micro-ultrasonic powder moulding method. The effect of ultrasonic exposure time on the microstructure and mechanical properties of the micro parts was investigated respectively by metallographic analysis, XRD and tensile testing. Reasonable process parameters for this method were determined, which were sonotrode pressure of 63.5 MPa, ultrasonic output power of 2475 W and ultrasonic exposure time of 1.5 s. 相似文献
136.
The anti-inflammatory effect and mechanism of Usnic acid (UA) were explored on lipopoly-saccharide (LPS)-stimulated RAW264.7 cell line.The effects of UA on pro-inflammatory cytokines including tumor necrosis factor-alfa (TNF-α),interleukin-6 (IL-6) and interleukin-1 beta (IL-1β),pro-inflammatory mediators such as nitric oxide (NO),inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were studied by sandwich ELISA,real-time PCR and western blot analyses.Similarly,the effect of UA on anti-inflammatory cytokine interleukin-10 (IL-10) and anti-inflammatory mediator heme oxygenase-1 (HO-1) were also studied following the same methods.Furthermore,nuclear factor-κB (NF-κB) was assayed by immunocytochemistry.The results showed that UA has anti-inflammatory effect by down-regulatinng iNOS,COX-2,IL-1β,IL-6 and TNF-α,COX-2 gene expression through the suppression of NF-κB activation and increasing anti-inflammatory cytokine IL-10 and anti-inflammatory mediator HO-1 production. 相似文献
137.
对进口的两种喷涂料进行实物剖析 ,研究了结合剂、掺和料、颗粒级配对喷涂料性能的影响 ,开发出QC - 140P、CN - 4 0P两种轻、重质喷涂料 ,替代进口产品 ,应用于氧化铝闪速焙烧炉 相似文献
138.
139.
Colloidal Moderate‐Refractive‐Index Cu2O Nanospheres as Visible‐Region Nanoantennas with Electromagnetic Resonance and Directional Light‐Scattering Properties
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140.
为解决无线分集相干光接收机的自适应盲检测问题,提出了一种新的离散时间连续状态的网络输出反馈偏置型的复Hopfield 神经网络用以解决多值QAM 信号的盲检测问题。反馈电压偏置的引入即不脱离传统Hopfield 模型,又能有效满足多值信号检测时所需的搜索空间变大的特殊要求。全文完成多值信号盲检测的优化问题构造和能量函数的映射,给出能量函数的证明、分析和它的约束条件,给出适用该问题的激活函数的基本特征,正确盲检测信号的权矩阵的配置方法。最后,通过详细的仿真结果展示和与其他算法性能对比进一步验证算法的有效性和优越性并指出算法所存在的问题和下一步的研究方向。 相似文献