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1.
胡航烨  王蔚 《应用声学》2023,42(1):76-83
情感语声合成技术对于人机交互具有重要的意义。面对儿童情感语声合成所需汉语语声数据资源缺乏以及模型训练时长较长等问题,该文提出利用迁移学习实现汉语儿童情感语声合成的方法。首先基于汉语语声数据库训练深度学习模型实现中文语声端到端合成模型,再使用高质量大样本的中文情感语料库完成情感语声合成模型,最后利用自行采样的小样本汉语儿童情感语料对模型进行迁移学习实现低资源的语声合成。客观实验结果中梅尔倒谱失真指标为4.91,主观听辨实验指标分别为3.61和4.17。通过实验对比表明,该文的方法在情感语声合成技术的应用上具有良好的性能表现,并且优于现有先进的低资源情感语声合成方法。  相似文献   

2.
A breakthrough in the technology of measuring systems of submicrometre and subsecond precision was made possible by the invention of holographic phase aperture synthesis of highly regular interference structures. The practical fulfilment of holographic phase aperture synthesis requires development of the following new optical methods: (1) synthesis of the aperture by out of phase auxiliary holographic diffraction gratings; (2) high-precision analysis of the phase structure of the interference field; (3) automatic control of the aperture synthesis process using two-frequency modulation of the interference field; (4) an adaptive interferometer for aperture synthesis. This paper is devoted to the above methods.  相似文献   

3.
罗经宇  钟文发 《计算物理》1986,3(3):311-323
本文着重介绍了综合法,并用加权剩余法对于R-Z几何的中子扩散方程推导了综合方程,同时叙述了综合方程的解法,并作了实例计算,与有限差分法比较,可大大地节省计算时间。  相似文献   

4.
A problem of fractal antenna radiation pattern synthesis is considered. The problem of synthesis of fractal antenna radiation patterns is solved for two kinds of antennas (discrete and linear) in one- and two- dimensional cases. With the use of the theory of fractal synthesis, new modes with new properties are obtained in fractal electrodynamics. Fractal radiation pattern synthesis was conducted by means of the Weierstrass function.  相似文献   

5.
Some information on the history of dynamic synthesis of diamond in Ukraine is considered. Basic characteristics of ASM5 0.1/0 and ASM1 0.1/0 nanodiamond powders produced by static synthesis are described. The characteristics and surface properties of nanodiamond powders produced by detonation synthesis in Ukraine are presented. It is shown that the chemical activity of the particle surface can be controlled. Applications of nanopowders produced by detonation synthesis in various technologies are considered.  相似文献   

6.
Zhang W  Lu Y  Chen CH 《Molecular diversity》2003,7(2-4):199-202
Coupling of microwave reactions with fluorous separations can dramatically increase the efficiency of high-speed synthesis. Described in this paper is a fluorous synthesis of aryl sulfides by palladium-catalyzed cross-coupling of aryl perfluoroalkylsulfonates (C8F17O2SOAr) with thiols (RSH) under microwave irradiation. Fluorous solid-phase extractions (F-SPE) are employed for the purification of reaction mixtures. No fluorous solvents are involved in reaction and separation processes. The fluorous synthesis is further extended to the multi-step synthesis of substituted hydantoin and amide scaffolds.  相似文献   

7.
We demonstrate a comparative study on graphene growth mechanism using various catalytic metal substrates such as Ni thin films, Ni-deposited Mo (Ni/Mo) sheets, and Pt sheets during chemical vapor deposition (CVD). Depending on the substrates, two kinds of graphene growth mechanisms that involve either precipitation or surface adsorption of carbon have been reported. We synthesized graphene, focusing especially on the initial growth stage during CVD, by varying synthesis parameters such as synthesis time, amount of feedstock, and cooling rate after synthesis. We concluded that precipitation-driven synthesis is dominant in the case of Ni substrates whereas adsorption-driven growth is dominant in the Ni/Mo system. In the case of the Pt substrate, which is generally believed to grow by carbon precipitation, graphene growth by adsorption was found to be dominant. We believe that our results will contribute to a clearer understanding of the graphene synthesis mechanism, and development of manufacturing routes for controllable synthesis of high-quality graphenes.  相似文献   

8.
Ultrasound (US) demonstrates remarkable potential in synthesising nanomaterials, particularly nanobiomaterials targeted towards biomedical applications. This review briefly introduces existing top-down and bottom-up approaches for nanomaterials synthesis and their corresponding synthesis mechanisms, followed by the expounding of US-driven nanomaterials synthesis. Subsequently, the pros and cons of sono-nanotechnology and its advances in the synthesis of nanobiomaterials are drawn based on recent works. US-synthesised nanobiomaterials have improved properties and performance over conventional synthesis methods and most essentially eliminate the need for harsh and expensive chemicals. The sonoproduction of different classes and types of nanobiomaterials such as metal and superparamagnetic nanoparticles (NPs), lipid- and carbohydrate-based NPs, protein microspheres, microgels and other nanocomposites are broadly categorised based on the physical and/or chemical effects induced by US. This review ends on a good note and recognises US-driven synthesis as a pragmatic solution to satisfy the growing demand for nanobiomaterials, nonetheless some technical challenges are highlighted.  相似文献   

9.
A real-time synthesis model of wind instruments sounds, based upon a classical physical model, is presented. The physical model describes the nonlinear coupling between the resonator and the excitor through the Bernoulli equation. While most synthesis methods use wave variables and their sampled equivalent in order to describe the resonator of the instrument, the synthesis model presented here uses sampled versions of the physical variables all along the synthesis process, and hence constitutes a straightforward digital transposition of each part of the physical model. Moreover, the resolution scheme of the problem (i.e., the synthesis algorithm) is explicit and all the parameters of the algorithm are expressed analytically as functions of the physical and the control parameters.  相似文献   

10.
A novel algorithmic approach to the synthesis of fairly long DNA molecules with nonrecurring sequences is demonstrated. The scheme exploits chemical embodiment of shift registers (SR) to execute algorithms similar to those used to generate pseudorandom numbers on a computer. Single stranded DNA molecules guide the synthesis of double stranded DNA according to the SR truth table. The SR logic facilitates an exponentially smaller synthesis effort compared with all other strategies. A redundancy based scheme, similar to those used in communication, is utilized to suppress synthesis errors.  相似文献   

11.
随机相位微波功率的空间合成效率   总被引:2,自引:1,他引:1       下载免费PDF全文
 采用数值计算方法,将微波功率源输出信号的相位差视为等概率分布的随机事件,通过阵列天线平均增益定量计算了多微波源空间功率合成效率;分析了随机相位条件下,天线单元间耦合系数、极化方式和单元增益对合成效率的影响。计算结果表明:多微波源在随机相位条件下进行空间功率合成,阵列天线单元之间的相互耦合将造成合成效率严重下降;而天线类型、极化方式和天线单元增益对合成效率的影响较小。  相似文献   

12.
贺存恒  古元新 《物理学报》1982,31(8):1057-1063
应用直接法程序系统MULTAN-78或者MULTAN-80解晶体结构,通常是在直接法找到部分原子位置后,用加权Fourier综合逼近,获得余下的原子位置。本文通过两个实例证明,当大部份原子已知时,尤其是结构含有重原子时,用不加权Fourier逼近比使用加权Fourier逼近更为有效。作者修改了MULTAN-80程序,使之增加了不加权Fourier综合的功能。 关键词:  相似文献   

13.
 本文研究了合成立方氮化硼用新触媒材料Mg3B2N4及Ca3B2N4的制备方法,并对它们的稳定性及其催化作用进行了讨论。氮化硼原料的结晶状态及合成温度、合成时间、气流量等对新触媒的合成有着重要的影响。本文还在高温高压下利用新触媒进行了立方氮化硼的合成实验,结果表明,与碱土金属触媒相比新触媒具有合成压力低、转化率高、合成温度和压力范围宽、产物杂志含量低、破碎强度高等优点,是一种应用前景很大的触媒材料。  相似文献   

14.
The underlying mechanism determining the size of a particular cell is one of the fundamental unknowns in cell biology. Here, using a new approach that could be used for most of unicellular species, we show that the protein synthesis and cell size are interconnected biophysically and that protein synthesis may be the chief mechanism in establishing size limitations of unicellular organisms. This result is obtained based on the free energy balance equation of protein synthesis and the second law of thermodynamics. Our calculations show that protein synthesis involves a considerable amount of entropy reduction due to polymerization of amino acids depending on the cytoplasmic volume of the cell. The amount of entropy reduction will increase with cell growth and eventually makes the free energy variations of the protein synthesis positive (that is, forbidden thermodynamically). Within the limits of the second law of thermodynamics we propose a framework to estimate the optimal cell size at division.  相似文献   

15.
胡美华  毕宁  李尚升  宿太超  李小雷  胡强  贾晓鹏  马红安 《物理学报》2013,62(18):188103-188103
对国产六面顶压机平台下使用多晶种法合成宝石级金刚石单晶进行了系统的研究. 通过合理调整温度梯度法的合成腔体组装, 采用多晶种法, 探索多晶种法金刚石合成的压力和温度区间, 在单个合成腔体内放置3–5颗金刚石晶种, 成功合成出多颗(3–5)优质Ib型宝石级金刚石单晶. 多颗晶种的引入, 单次实验合成的多个金刚石晶体晶形及品质一致; 同时, 晶体的整体生长速度也有明显的增大. 多晶种法金刚石单晶合成的研究, 可以有效地利用腔体空间、提高单次金刚石单晶合成的效率, 解决压机大型化下高温高压资源利用率低的问题; 同时, 为宝石级金刚石单晶商业化生产提供重要的依据. 关键词: 金刚石 国产六面顶 多晶种 温度梯度法  相似文献   

16.
The technologies enabling the creation of large scale, miniaturized peptide or protein microarrays are emerging. The focuses of this review are the synthesis and applications of peptide and peptidomimetic microarrays, especially the light directed parallel synthesis of individually addressable high density peptide microarrays using a novel photogenerated reagent chemistry and digital photolithography (Gao et al., 1998, J. Am. Chem. Soc. 120, 12698; Pellois et al. 2002, Nat. Biotechnol. 20, 922). Concepts related to the synthesis are discussed, such as the reactions of photogenerated acids in the deprotection step of peptide synthesis or oligonucleotide synthesis, and the applications of high density peptide chips in antibody binding assays are discussed. Peptide chips provide versatile tools for probing antigen-antibody, protein-protein, peptide-ligand interactions and are basic components for miniaturization, automation, and system integration in research and clinical diagnosis applications.  相似文献   

17.
全固态快沿脉冲源具有小型化、高稳定性、高重复频率、输出功率低等特点,为了克服单个脉冲源输出功率低的问题,利用ADS仿真软件建立了多节蛇形微带线结构的功率合成器,并用实验验证了功率合成的效果。利用两路高稳定度的脉冲子源作为功率合成的两路输入,通过该功率合成器使两路快沿双指数信号合成为一路快沿双指数信号,实现了功率的提高。实验中脉冲子源的幅度为1.1 kV, 前沿约为2 ns,脉冲宽度为10 ns;两路信号合成后,输出电压为1.6 kV, 前沿约为2 ns,脉冲宽度为18 ns。实验验证了该功率合成模块的可行性,该合成模块还可推广至多路的脉冲子源的功率合成,实现提高快沿双指数脉冲功率的目的。  相似文献   

18.
The preparation of LaMnO3 from various precursors via a solid-state reaction combined with codeposition and sorption is found to form perovskite phases with different stoichiometric deviations, depending on the temperature of synthesis. This favors the coexistence of orthorhombic (in solid-phase synthesis) and rhombohedral (in wet synthesis) phases at room temperature.  相似文献   

19.
By fulfilling the specific design criteria required for safe and reproducible microwave synthesis, Personal Chemistry introduced the first microwave system designed for organic chemistry in 2000. The principle of microwave synthesis offers 3 major benefits to chemistry development: speed, reproducibility, and a scalable approach to compound synthesis. Additionally, significant advantages of our technical solution are ease of use, safety, verified synthesis methods to enable new users, and an efficient workflow that fits the drug discovery process. To gain the greatest advantages offered by microwave synthesis, Personal Chemistry has implemented a system called Coherent Synthesis. Incorporating planning systems, automation, distributed system access, searchable databases and reaction optimisation kits, the technology has already proved itself to dramatically improve the quality of output from medicinal chemistry for lead optimisation in all the major pharmaceutical and biotech companies.  相似文献   

20.
Abstract

A new solvothermal route for the synthesis of nitrides is proposed using liquid NH3 as solvent in supercritical conditions, Such a preparation method was applied to the synthesis of GaN using gallium metal as starting material.

GaN is a wide band-gap semi-conductor (3.4eV). It is a very attractive nitride due to its various applications in micro- and opto-electronics [1,2]. Consequently, many research groups are interested in synthesising GaN. Two methods have been principally developed:

(i) synthesis of thin films by epitaxy [3,4]

(ii) synthesis of bulk GaN by high pressure method [5,6].

The new proposed process leads to fine microcrystallites of GaN with the wurtzite-type structure. The chemical purity can be optimised versus the synthesis mechanism. The size and shape of the crystallites would be influenced by the nature of the nitriding additive and the thermodynamical conditions (pressure and temperature) used for the synthesis.  相似文献   

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