噪声情况下采用稀疏非负矩阵分解与深度吸引子网络的人声分离算法

为实现噪声情况下的人声分离,提出了一种采用稀疏非负矩阵分解与深度吸引子网络的单通道人声分离算法。首先,通过训练得到人声与噪声的字典矩阵,将其作为先验信息从带噪混合语音中分离出人声与噪声的系数矩阵;然后,根据人声系数矩阵中不同的声源成分在嵌入空间中的相似性不同,使用深度吸引子网络将其分离为各声源语音的系数矩阵;最后,使用分离得到的各语音系数矩阵与人声的字典矩阵重构干净的分离语音。在不同噪声情况下的实验结果表明,本文算法能够在抑制背景噪声的同时提高分离语音的整体质量,优于结合声噪人声分离模型的对比算法。      

基于自制超稳定F-P腔压窄632.8nm外腔半导体激光线宽的实验研究

窄线宽激光由于其具有单色性好、稳定度高、相干长度长等优点,广泛应用于光电检测领域,包括相干通信、精密测量、光学频率标准、吸收光谱计量以及光与物质相互作用研究等.目前频率稳定的氦氖激光器线宽可以达到M Hz量级,分布反馈式(DFB)光纤激光器线宽可达kHz量级,DFB半导体激光器线宽可以达到M Hz量级,然而光栅反馈半导...     

连体构架避雷针风振计算的简化方法

为简化构架避雷针风振时域计算从而有效降低计算耗时,以单跨和三跨构架避雷针结构为例,根据构架体系的结构特性和风振特点,提出一种简化计算方法,即对每个塔架单独建模并考虑结构刚度和质量系统的一致性和横梁荷载的等效加载,从而对每个塔架单独进行动力计算,并对这种简化方法的合理性进行了验证。研究发现,构架避雷针的频率较小,风振效应较为显著,但在各方向均以一阶振型为绝对主力;构架避雷针的塔架在平面外的荷载耦联效应极小,平面内也仅表现有位移均值的耦联效应:这两个结构特性也为风振简化计算提供了便利。对每个塔架的简化模型,通过在塔架与原横梁连接处设置弹簧和附加质量来实现对原结构一阶振型的等效,并通过影响线法将横梁分布风荷载等效为塔架的集中荷载。由此简化方法所得的结构风振静动力响应结果均与原始结构有良好一致性,并且计算效率得以显著提升。     

温度对PEEK太赫兹光谱特性影响研究

聚醚醚酮(PEEK)由于其耐热、耐腐蚀、耐辐照、抗疲劳、电绝缘性等优良性能,在许多领域可以代替金属、陶瓷等传统材料而得到广泛应用。特别是随着5G技术的发展和应用,PEEK已经成为5G热门材料。在PEEK材料实际应用中,温度的影响是一个非常重要和关键的因素。主要研究了PEEK太赫兹光谱以及温度对PEEK太赫兹光谱特性的影响。通过利用太赫兹透射光谱技术,同时结合控温装置,在温度从25～300℃均匀上升过程中,每间隔5℃测试得到PEEK片状样品的太赫兹时域光谱数据,利用光学参数提取算法可以得到PEEK的吸收系数、介电常数等光学参数,进一步得到特定频率下光学常数随温度的变化趋势,从而对材料进行表征和分析。在0.5～4 THz有效光谱范围内,实验结果表明,在常温(25℃)下,PEEK在3.5 THz具有一个明显的特征吸收峰。在25～300℃这个温度范围内,在1 THz频率下,PEEK的吸收系数、介电常数相对于室温分别有4.38%和5.0%的波动,同时PEEK在常温下在1 THz的介电损耗正切值为2.5×10^-3,相比于PMMA和PE等高分子材料,PEEK的介电损耗正切值要低...     

Synthesis,Crystal Structure and Antimicrobial Property of 4-Bromo-2-[(3-methypyridin-2-ylimino)methyl]phenol

The title Schiff base compound 4-bromo-2-[(3-methylpyridin-2-ylimino)me-thyl]phenol was prepared and structurally characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/n,with a=4.4870(9),b=19.953(4),c=13.860(3)(A),β=93.13(3)°,V=1239.O(4)(A)3,Z=4,Dc=1.561g/cm3,C13H11BrN2O2,Mr=291.15,μ=3.302mm-1 and F(000)=584.The final refinement gave R =0.0608 and wR=0.1377 for 1329 observed reflections with I＞2σ(I).X-ray diffraction reveals that the non-hydrogen atoms in the compound are nearly coplanar,with the mean deviation of 0.0197 (A) from the plane.The molecule adopts an E configuration about the central C=N functional bond.The compound possesses moderate antimicrobial property.     

A Novel （4,6）-Connected Net Based on Dysprosium Benzenedicarboxylate, [Dy（OAc）（BDC）]n

A new lanthanide coordination polymer, [Dy（OAc）（BDC）]n 1 （OAc = acetate, BDC = 1,4-benzenediacarboxylate）, has been synthesized under hydrothermal conditions. Single-crystal X-ray diffraction analysis reveals that complex 1 has infinite zigzag Dy-OAc chains, which are further connected by BDC to form a 3D metal-organic framework. According to topology analysis, this framework can be characterized as （4,6）-connected （3.4.54）（32.4.56.66） net that has never been reported before. Crystal structure for 1： space group Pbca, a = 13.314（3）, b = 8.0269（18）, c = 20.275（5）A, V= 2166.8（9）A3, C10H7O6Dy, Mr = 385.66, Z= 8, Dc = 2.364 g/cm^3, μ= 6.910 mm^-1, F（000） = 1448, the final R = 0.0181 and wR = 0.0520.     

Synthesis and Crystal Structure of a New Double 2D Layer Complex Assembled by H4btec

Assembly of H4btec with cobalt（Ⅱ） acetate afforded a new double 2D layer coordination polymer, [Co（bteC）1/2（H2O）4·2H2O]n （H4btec = benzene-1,2,4,5-tetracarboxylic acid） 1. The polymeric structure has been characterized by single-crystal X-ray diffraction, FT-IR and thermal analysis. The crystal is of triclinic, space group PI with a = 10.8762（2）, b = 11.1411（1）, c = 11.5084（3） A, a = 82.8950（10）, β = 63.0050（10）, γ = 62.1500（10）°, V = 1091.72（4） A^3, C5H13CoO10, Mr= 292.08, Z = 4, Dc = 1.777 g/cm^3, μ = 1.612 mm^-l, F（000） = 600, R = 0.0578, and wR = 0.2162 for 3576 observed reflections （Ⅰ 〉 2σ（Ⅰ））. Complex 1 consists of a new double 2D layer structure [Co（btec）1/2（H2O）4]n, both consisting of 4 ＋ 4 grids with the sizes of 11.3667（2）A × 11.5084（3）A （Co（1）-Co（1A） × Co（2A）-Co（2B）） and 11.5084（3）A × 11.3667（2）A （Co（3）-Co（3C） × Co（4）- Co（4A））, respectively. The phenyl rings are at the comers while the Co（Ⅱ） atoms are in the sides of the grids, and lattice water molecules decorate between the layers. Hydrogen bonds between the layers and lattice water molecules result in the final 3D framework.     

Synthesis and Molecular Structure of 3-（p-Methoxyphenyl）-4-hydroxymethyl-6-bromo- 7-hydroxycoumarin Co-crystallized with Methanol

The title compound, C18H17BrO6 （Mr = 409.23）, was synthesized as angiogenesis inhibitor and structurally characterized by ^1H-NMR, ^13C-NMR, MS, elemental analysis and X-ray single-crystal diffraction. Structure analysis indicates that the title compound is of triclinic, space group P1^-, with a = 8.100（3）, b = 10.536（4）, c = 11.689（5）A, a = 67.405（7）, βl = 69.736（3）, γ = 88.510（5）°, V = 857.3（5） A^3, Z = 2, Dc = 1.585 g/cm^3, μ = 2.429 mm^-1, F（000） = 416, the finial R = 0.0356 and wR = 0.0929 for 2541 observed reflections. The bond lengths of C（7）-C（16） proved that the title compound possesses coumarin rather than flavone scaffold.     

顺铂前药接枝修饰硫代DNA及其自组装靶向纳米药物研究

选用具有良好生物相容性的硫代修饰嵌段核酸为载体,将其非硫代修饰部分设计为靶向MUC-1蛋白的核酸适配体序列,同时在其硫代修饰部分通过硫代磷酸酯基团(Phosphorothioate, PS)接枝修饰四价顺铂前药,制备了两亲性核酸-顺铂前药缀合物MUC-1/^PODNA-b-(^PSDNA-g-Pt),并进一步自组装成类似球形核酸(Spherical nucleic acid, SNA)的含铂靶向纳米药物(MUC-1/Pt-SNAs).结果表明,该纳米药物递送体系载药率高、形貌稳定、分散性好,能够高效靶向MUC-1蛋白过表达的MCF-7乳腺癌细胞,并在体内外实验中表现出优异的抗肿瘤效果和极低的毒副作用.     

Schwarz Lemma at the Boundary on the Classical Domain of Type Ⅲ

Let R_Ⅲ(n) be the classical domain of type Ⅲ with n≥2. This article is devoted to a deep study of the Schwarz lemma on R_Ⅲ(n) via not only exploring the smooth boundary points of R_Ⅲ(n) but also proving the Schwarz lemma at the smooth boundary point for holomorphic self-mappings of R_Ⅲ(n).