排序方式: 共有47条查询结果,搜索用时 15 毫秒
1.
Jian-binSong Min-qiaoRen Qing-yongChen Shu-yunWang Qing-xiangZhao Hong-fangZhang 莫志深 《高分子科学》2004,(5):491-496
Based on the X-ray scattering intensity theory and using the approximate expression for the atomic scattering factor, the correction factors for three crystalline peaks and an amorphous peak of Nylon 1212 were calculated and the formula of degree of crystallinity of Nylon 1212 was derived by a graphic multipeak resolution method. The degree of crystallinity calculated from the WAXD method is compatible with those obtained by density and calorimetry methods. 相似文献
2.
The electromagnetic ultrasound is used in the detection of interfaces of the adhesive multilayer structures to solve the unstable coupling problem in ultrasonic testing by traditional piezoelectric transducers. Based on the analysis of the transforming mechanism of electromag-netic ultrasound energy and the resultant dead zone from mutual inductance of the transducer, the wavelet filtering by soft-thresholding and adaptive noise canceling methods are used simul-taneously to the detected electromagnetic ultrasonic signals to overcome the drawbacks of the low signal to noise ratio (SNR) and the wide intrinsic dead zone of the transducer. Processed results in the interface detection of a three layered adhesive sample of steel and rubber materials demonstrate that the wavelet filtering enhances the SNR about 12dB while the adaptive noise canceling narrows the dead zone effectively. 相似文献
3.
ZHANG Qi-Wei WANG Gui-Xian 《结构化学》2007,26(5):551-554
The title compound, [Cu(dpa)(2,2'-bipy)(H2O)2]n 1 (H2dpa = diphenic acid and 2,2'- bipy = 2,2'-bipyridine), has been synthesized and its structure was determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group P212121 with a = 10.597(4), b = 11.317(4), c = 17.630(7) , V = 2114.3(14) 3, C24H20CuN2O6, Mr = 495.97, Z = 4, Dc = 1.558 g/cm3, μ = 1.079 mm-1, F(000) = 1020, Flack value = 0.052(18), R = 0.0430 and wR = 0.1016 for 3381 observed reflections (I > 2σ(I)). In compound 1, the dpa ligands link metal ions into helical structures in the same direction. 相似文献
4.
Simple and robust digital holography for high-resolution imaging 总被引:2,自引:0,他引:2
Based on the point spread function of holographic system,the lateral resolution of digital holographic imaging system without any pre-magnification is studied.The expression of resolution limitation of holographic imaging system is thus presented.We investigate the possibilities to improve the lateral resolution.The simple experimental setup with an off-axis arrangement is built.By using a U.S.Air Force(USAF)test target as microscopic object,the recorded holograms are reconstructed digitally based on the principle of Fresnel diffraction.The lateral resolution of 2.76 μm without any pre-magnification is demonstrated experimentally,which matches the theoretical prediction well. 相似文献
5.
Closely packed dense frequency selective surface 总被引:1,自引:0,他引:1
In order to realize wideband filtering properties of frequency selective surface (FSS), FSS of closely packed elements is presented. The Y loop elements are chosen as the graphics elements. Based on the spectral domain method, the frequency response is analyzed for different incident angles and polarizations. The result of the numerical analysis shows that the dense FSS has wide passband with better independence of angle and polarization. 相似文献
6.
提出了用火焰原子吸收光谱法测定高铝锌基合金中镁的方法,在测定条件下,共存元素的干扰可消除,能测定高铝锌基金合中0.001-0.01%,范围内的镁,该方法相对标准偏差<6%,样品加标回收率为94-102%。 相似文献
7.
建立了ICP-AES同时测定铋系超导材料中Bi、Pb、Sr、Ca、Cu5种金属元素含量的分析方法,优化了仪器的最佳工作条件。该方法无需复杂的前处理,没有谱线和基体干扰,检出限Bi为0.01699μg.mL^-1、Pb为0.02121μg.mL^-1、Sr为0.002854μg.mL^-1、Ca为0.007401μg.mL^-1、Cu为0.003726μg.mL^-1。该法相对误差均小于1.0%,RSD均小于1.0%,简便,快捷,完全满足铋系超导材料中各元素含量的测定。 相似文献
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9.
CHENG Li-Chuan LI Hao-Hong CHEN Zhi-Rong LI Jun-Qian HUANG Chang-Cang CAI Zeng-Liang 《结构化学》2007,26(11)
A new lead(Ⅱ) iodide coordination polymer [(npq)(PbI3)]n 1 (npq = N-propyl- quinolinium) has been synthesized in the presence of npq as structure-directing reagent (SDA). Compound 1 crystallizes in the orthorhombic system, space group Pbca, with a = 19.158(4), b = 7.9909(16), c = 22.929(5) (A), V = 3510.2(12) (A)3, Z = 8, Dc = 2.877 g/cm3, F(000) = 2672, C12H14I3NPb, Mr = 760.14, μ(MoKα) = 14.872 mm-1, the final R = 0.0431 and wR = 0.1021 for 3678 observed reflections with I>2σ(I). Structure determination indicates that the [PbI3]-n infinite chains in each unit cell shape the sketch of 1, which could be described as the result of face-sharing distorted PbI6 octahedra running along the b axis. Electrostatic interaction between conjugated organic counter-cations and inorganic moieties presents and contributes to the crystal packing. 1 was further characterized with IR and elemental analysis. Based on the crystal structure data, quantum chemical calculation with DFT method was used to reveal the electronic structure and optical property of 1. 相似文献
10.
Dr. Dechao Zhang Dr. Yuxuan Liu Zhaoyu Sun Dr. Zhengbo Liu Dr. Xijun Xu Lei Xi Prof. Shaomin Ji Prof. Min Zhu Prof. Jun Liu 《Angewandte Chemie (International ed. in English)》2023,62(44):e202310006
The deployment of lithium metal anode in solid-state batteries with polymer electrolytes has been recognized as a promising approach to achieving high-energy-density technologies. However, the practical application of the polymer electrolytes is currently constrained by various challenges, including low ionic conductivity, inadequate electrochemical window, and poor interface stability. To address these issues, a novel eutectic-based polymer electrolyte consisting of succinonitrile (SN) and poly (ethylene glycol) methyl ether acrylate (PEGMEA) is developed. The research results demonstrate that the interactions between SN and PEGMEA promote the dissociation of the lithium difluoro(oxalato) borate (LiDFOB) salt and increase the concentration of free Li+. The well-designed eutectic-based PAN1.2-SPE (PEGMEA: SN=1: 1.2 mass ratio) exhibits high ionic conductivity of 1.30 mS cm−1 at 30 °C and superior interface stability with Li anode. The Li/Li symmetric cell based on PAN1.2-SPE enables long-term plating/stripping at 0.3 and 0.5 mA cm−2, and the Li/LiFePO4 cell achieves superior long-term cycling stability (capacity retention of 80.3 % after 1500 cycles). Moreover, Li/LiFePO4 and Li/LiNi0.6Co0.2Mn0.2O2 pouch cells employing PAN1.2-SPE demonstrate excellent cycling and safety characteristics. This study presents a new pathway for designing high-performance polymer electrolytes and promotes the practical application of high-stable lithium metal batteries. 相似文献