基于帧特征、段特征联合建模的语音识别模型

提出了基于帧特征、段特征联合建模的语音识别模型。该模型采用描述谱参数轨迹的段特征,在段尺度上实现了对语音信号帧间相关性的显式建模;采用段特征依赖的非平稳时间序列产生模型,实现了段特征与帧特征间的相关性建模,并在帧尺度上通过参数化的均值轨迹函数,实现了对语音信号帧间相关性的隐式建模。本文给出了基于帧特征、段特征联合统计距离优化的分段算法以及内嵌ＥＭ迭代的模型参数估计算法。对非特定人汉语孤立韵母以及多话者汉语基本音节的识别实验表明,该模型的识别性能优于标准ＨＭＭ及趋势ＨＭＭ。     

PPt课件对课堂演示实验的互补作用

在PPt课件中利用动画模拟演示实验是必要的,其教学效果值得关注。     

丁基锡炔基膦酸酯的合成

本文合成了１０个新的二（三）丁基锡炔基膦酸酯「（ｎ－（Ｃ４Ｈ９）ｎＳｎ」ｎ－１Ｏ２Ｐ（Ｏ）Ｃ≡ＣＲ（ｎ＝２,３;Ｒ＝ｎ－Ｃ５Ｈ１１,ｎ－Ｃ６Ｈ１３,Ｐｈ,ＣＨ２ＯＭｅ,ＣＨ２ＯＥｔ）通过元素分析,ＩＲ和＾１Ｈ ＮＭＲ确证了其结构。     

硫酸铜催化合成二元酸系列酯

以硫酸铜为催化剂,合成了２０种二元酸系列酯,结果表明,该催化剂具有活性好、操作简便、无三度污染、酯收率高、可多次重复使用等优点。经正交试验得出已下酯较佳的合成工艺条件。     

吡啶基羧酸苄基锡配合物的红外光谱

研究了７ 种吡啶基羧酸苄基锡配合物的红外光谱, 归属了它们的主要红外吸收峰, 探讨了它们随化学结构而变化的规律, 确定了吡啶基羧酸与锡原子的配位形式。     

Bending of a circular cylinder containing a crack

The study of bending of cracked circular cylinders is of more significance. The bending of cylinders containing radical crack or cracks was discussed by refs. [1]–[4] and that of concentrically craked circular cylinders was studied by [5]. Continuing [6] and using complex variable methods in elasticity, this paper deals with the bending problems of a circular cylinder, containing an internal linear crack at any position under an acting force perpendicular to the crack. The general forms of displacements, stresses, and stressintensity factors, expressed in terms of series, are obtained and to this bending problems with small Ah are presented good approximate formulas for the stress-intensity factors whose variations with the center of the crack are analysed. Finally, the twist angle per unit length and the center of bending for the radically cracked circular cylinder, one of whose crack-tips is located at the origin, have been computed and the results are almost the same as that calculated in [1].     

二{氧桥-二[N,N-二甲基(或乙基)氨荒酸基乙酸二丁基锡(Ⅳ)]}的合成及结构

利用二丁基氧化锡与N,N-二甲基氨荒酸基乙酸以及N,N-二乙基氨荒酸基乙酸反应,合成了二聚体有机锡化合物{[n-Bu2Sn(O2CCH2CS2NMe2)]2O}2 (1)和{[n-Bu2Sn(O2CCH2CS2NEt2)]2O}2 (2).通过元素分析,红外光谱及核磁共振谱对它们进行了表征.并用X射线单晶衍射法测定了这两个化合物的晶体结构,结果表明1为单斜晶系,C2/m空间群,晶胞参数为a=1.3584(5) nm, b=1.9242(7) nm, c=1.4640(5) nm, β=102.505(5)°, Z=2, V=3.736(2) nm3, μ=1.490 g/cm3, F(000)=1704, R1=0.0492, wR2=0.1159. 2为三斜晶系,P1-空间群,晶胞参数为a=1.1960(14) nm, b=1.3612(16) nm, c=1.3684(16) nm, α=90.969(18)°, β=105.241(17)°, γ=103.954(16)°, Z=1, V=2.078(4) nm3, μ=1.429 g/cm3, F(000)=916, R1=0.0459, wR2=0.0957.它们都是以Sn2O2四元环为中心对称的二聚体结构.但锡原子的配位方式不同,在1中,内外环锡原子均为五配位的畸变三角双锥构型;而在2中,内环锡原子为五配位的畸变三角双锥构型,而外环锡原子为六配位的加帽三角双锥构型.     

类风湿关节炎免疫吸附剂载体-碳化树脂的制备及性能研究

以苯乙烯、丙烯腈为单体,二乙烯苯为交联剂,添加一定量的致孔剂,在水相中采用分步聚合工艺制成高分子树脂,再经高温碳化制备碳化树脂.研究结果表明,单体交联度为35%时,碳化树脂比表面积达到601m2/g.用该碳化树脂包埋DNA后对类风湿因子IgG、IgM、IgA的吸附清除率达到了52.9%、58.5%、37.0%.     

Synthesis and Crystal Structure of the Mixed-quadriligand Bismuth Complex [Bi(S2CNEt2)2(NO3)]·[1,10-Phen]

The mixed-quadriligand bismuth complex [Bi(S2CNEt2)2(NO3)]([1,10-Phen] has been synthesized, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.074(17), b = 15.05(2), c = 18.99(3)(°A), β = 98.85(3)o, V = 2845(8)(°A)3, Z = 4, F(000) = 1464, Dc = 1.746 g/cm3, μ = 6.523 mm-1, R = 0.0333 and wR = 0.0703. In this complex, the bismuth atom is eight-coordinated in a capped distorted pentagonal bipyramidal geometry.     

氧化石墨烯量子点对鸡卵清蛋白递送-免疫增强佐剂效力评估

利用改进的Hummers法氧化鳞片石墨,获得富含羟基和羧基的氧化石墨烯量子点(GOQDs)。通过透射电子显微镜、X射线衍射、红外光谱及拉曼光谱测试表征其理化性质。此外,利用鸡卵清蛋白(OVA)作为模式抗原,构筑GOQDs/OVA纳米疫苗并评估其载量、安全性、免疫效力等。结果显示,GOQDs/OVA纳米疫苗直径在5nm左右,具有高度的水分散性和稳定性。其对OVA的最大负载量约为 500mg·g^-1,在pH=5.5和7.4环境下24 h的释放率分别为74.65%和56.93%,表现出pH刺激响应释放性能。当GOQDs浓度在500μg·mL^-1以下时,不会引起溶血、细胞损伤、重要组织发生病变等现象。免疫后,与 OVA单独免疫对照组相比,GOQDs/OVA纳米疫苗可以诱导产生高水平的免疫球蛋白G(IgG)、免疫球蛋白G1(IgG1)及免疫球蛋白G2a(IgG2a)抗体,提高白细胞介素(IL)-1β、IL-2、IL-4和IL-6、肿瘤坏死因子-α(TNF-α)和γ干扰素(IFN-γ)的分泌,同时促进脾中辅助性(CD4⁺)和细胞毒性(CD8⁺)T淋巴细胞百分比的增加。