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71.
Robert Brooke Manrico Fabretto Samuel Pering Eliza Switalska Lachlan Reeks Drew Evans Peter Murphy 《应用聚合物科学杂志》2015,132(26)
A study using three different pairs of electrochromic polymers (ECPs) synthesized onto plaques by means of a modified vapor phase polymerization (VPP) technique is presented. Restriction of the respective polymerization times, allowed both faster and slower polymerizing monomers to be controlled, and produced blended plaques with visually diffuse interfaces. The ECPs within the blended plaques retain their individual electrochromic behavior and when encapsulated into an electrochromic device, show outstanding optical switching performance with little degradation evident over 10,000 cycles, coupled with a switching time of the order of 1 second. Blends also allow multiple diffuse color changes within an electrochromic device, due to the difference in oxidation potentials of the individual ECPs, making them candidates for adaptive camouflage use. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42158. 相似文献
72.
Shruti Mendiratta Cheng-Hua Lee Muhammad Usman Kuang-Lieh Lu 《Science and Technology of Advanced Materials》2015,16(5)
Metal–organic frameworks (MOFs) have been intensively studied over the past decade because they represent a new category of hybrid inorganic–organic materials with extensive surface areas, ultrahigh porosity, along with the extraordinary tailorability of structure, shape and dimensions. In this highlight, we summarize the current state of MOF research and report on structure–property relationships for nonlinear optical (NLO) and dielectric applications. We focus on the design principles and structural elements needed to develop potential NLO and low dielectric (low-κ) MOFs with an emphasis on enhancing material performance. In addition, we highlight experimental evidence for the design of devices for low-dielectric applications. These results motivate us to develop better low-dielectric and NLO materials and to perform in-depth studies related to deposition techniques, patterning and the mechanical performance of these materials in the future. 相似文献
73.
Bun-Hee Lee Young-Min Park Seung-Hwan Lee Miseon Shim 《International journal of molecular sciences》2015,16(3):6251-6265
Background: Animal and clinical studies have demonstrated that the loudness dependence of auditory evoked potentials (LDAEP) is inversely related to central serotonergic activity, with a high LDAEP reflecting weak serotonergic neurotransmission and vice versa, though the findings in humans have been less consistent. In addition, a high pretreatment LDAEP appears to predict a favorable response to antidepressant treatments that augment the actions of serotonin. The aim of this study was to test whether the baseline LDAEP is correlated with response to long-term maintenance treatment in patients with major depressive disorder (MDD). Methods: Scalp N1, P2 and N1/P2 LDAEP and standardized low resolution brain electromagnetic tomography-localized N1, P2, and N1/P2 LDAEP were evaluated in 41 MDD patients before and after they received antidepressant treatment (escitalopram (n = 32, 10.0 ± 4.0 mg/day), sertraline (n = 7, 78.6 ± 26.7 mg/day), and paroxetine controlled-release formulation (n = 2, 18.8 ± 8.8 mg/day)) for more than 12 weeks. A treatment response was defined as a reduction in the Beck Depression Inventory (BDI) score of >50% between baseline and follow-up. Results: The responders had higher baseline scalp P2 and N1/P2 LDAEP than nonresponders (p = 0.017; p = 0.036). In addition, changes in total BDI score between baseline and follow-up were larger in subjects with a high baseline N1/P2 LDAEP than those with a low baseline N1/P2 LDAEP (p = 0.009). There were significantly more responders in the high-LDAEP group than in the low-LDAEP group (p = 0.041). Conclusions: The findings of this study reveal that a high baseline LDAEP is associated with a clinical response to long-term antidepressant treatment. 相似文献
74.
Zhuo Shi Ningning Dong Dingfeng Zhang Xiaofang Jiang Guanxin Du Shichao Lv Jiejie Chen Jun Wang Shifeng Zhou 《Journal of the American Ceramic Society》2019,102(7):3965-3971
The construction of nonlinear optical materials featuring asymmetric transmission of light is of great technological importance for various applications, including optical switching and optical power limiting. A significant challenge is the scalable fabrication of material candidates with good photochemical stability, high optical transmittance, and excellent optical limiting performance. Here, we present a nanocrystallization avenue for constructing hybrid optical limiting materials that exhibit ultrafast and robust optical limiting performance. The experimental results show that the controllable relaxation of a niobate glass may lead to the clustering of Nb-O units and contracting of the bandgap. It results in the notable improvement in nonlinear optical properties, including the enhanced saturation irradiance (380 GW/cm2), doubly increased nonlinear coefficient, and decreased limiting threshold (200 GW/cm2). Our results suggest a promising material that exhibits promising applications for protecting eyes and sensitive components from laser-induced damage. 相似文献
75.
76.
Evolution of the microstructure, optical, and magnetic properties have been investigated systematically in multiferroic CuFe1-xSnxO2 (x?=?0–0.05) ceramics. Substitution of Sn4+ for Fe3+ results in expansion of CuFeO2 lattice, and reduces the density of the material, but the metal oxidation states are unchanged. Observation of the optical properties shows that the value of the direct optical band gap (Eg) decreases with increasing Sn doping level, and that the CuFe1-xSnxO2 (x?=?0–0.04) series with values >?3.1?eV. Magnetic susceptibility measurements show that Sn4+ doping decreases the Curie-Weiss temperature, i.e. weakens the strength of the antiferromagnetic interaction between high-spin Fe3+ ions, but does not affect the stability of the antiferromagnetic phase, and all samples undergo successive magnetic transitions at about TN1 =?15?K and TN2 =?11?K. However, magnetization curves show that changes occur in the magnetic interactions and both ferromagnetism and antiferromagnetism co-exist in the Sn4+-doped samples. The maximum value of the saturation magnetization of 1.8?emu·g?1 was observed for the x?=?0.03 sample in a 2.5?kOe field. The changes in the magnetic behavior are closely related to the lattice distortion and charge compensation, which are discussed in detail in this work. 相似文献
77.
首先介绍低温共烧陶瓷(LTCC)技术和数字光收发模块,阐述LTCC的技术特点、工艺流程以及它相较于传统PCB电路基板的优势,解释了数字光收发模块的通信原理和工作方式;其次,提出了一种基于LTCC电路基板的数字光收发模块的设计方案,详细介绍了该光模块的主要构成和实现方法,包括电路设计和关键器件的比较和选取;最后,通过对该方案所述的数字光收发模块的样件进行关键指标和性能测试,验证了该设计方案的可行性。 相似文献
78.
79.
Casey Jessop Johan Ahlstrm Christer Persson Yubin Zhang 《Fatigue & Fracture of Engineering Materials & Structures》2020,43(1):201-208
Rolling contact fatigue cracks and thermally induced defects are common problems in the railway industry especially as demands for increasing loads, speeds, and safety continue to rise. Often, the two types of defects are found together in the field, however, whether one causes the other to occur is not completely agreed upon. The effect of thermal damage, in the form of a martensite spot on pearlitic steel test bars, on the fatigue life in uniaxial low cycle fatigue experiments was investigated by the authors. However, the focus of the current work was to characterize the damage evolution from the low cycle fatigue (LCF) tests and correlate the crack initiation and propagation with the initial thermal damage. Residual stress measurements, digital image correlation, and X‐ray tomography were used to characterize the effects of the thermal damage before, during, and after fatigue testing, respectively. It was found that the thermal damage causes strain accumulation and crack initiation at the interface between the two materials. The strain evolution was visualized using digital image correlation (DIC), clearly showing the strain concentrations at the top and bottom of the white etching layers (WEL), where the residual stresses are also most tensile. X‐ray tomography confirmed the planar crack growth from the martensite spot. 相似文献
80.
Jinghan Zhu Haixin Lin Youngeun Kim Muwen Yang Kacper Skakuj Jingshan S. Du Byeongdu Lee George C. Schatz Richard P. Van Duyne Chad A. Mirkin 《Advanced materials (Deerfield Beach, Fla.)》2020,32(8):1906600
A novel method for synthesizing and photopatterning colloidal crystals via light-responsive DNA is developed. These crystals are composed of 10–30 nm gold nanoparticles interconnected with azobenzene-modified DNA strands. The photoisomerization of the azobenzene molecules leads to reversible assembly and disassembly of the base-centered cubic (bcc) and face-centered cubic (fcc) crystalline nanoparticle lattices. In addition, UV light is used as a trigger to selectively remove nanoparticles on centimeter-scale thin films of colloidal crystals, allowing them to be photopatterned into preconceived shapes. The design of the azobenzene-modified linking DNA is critical and involves complementary strands, with azobenzene moieties deliberately staggered between the bases that define the complementary code. This results in a tunable wavelength-dependent melting temperature (Tm) window (4.5–15 °C) and one suitable for affecting the desired transformations. In addition to the isomeric state of the azobenzene groups, the size of the particles can be used to modulate the Tm window over which these structures are light-responsive. 相似文献