氟钽酸钾中微量碳的测定

为了完全消除氟钽酸钾试样中的氟对燃烧法测定其中微量碳的影响,提出用铝片包裹试样,在８８０℃通氧燃烧时,试样中的氟与铝形成不易挥发的氟化铝,从而使大部分氟保留在瓷料中。尚有残留的少量氟逸出,可使经过装有２－「５－（８－羟基喹啉）偶氮』－４－,５－二苯基咪唑和二氧化锰的分离柱而完全除去。试样中微量碳最终用库仑不测定。     

Infrared Optical Absorptions in Corrugated Lateral Surface Superlattices

The optical properties are investigated numerically in infrared (IR) regions for GaAs/AIAs corrugated lateral surface superlattices (CLSSLs) with short lateral periods. The calculations are carried out for refractive indexes and optical absorption coefficients with and without inclusion of electron interactions in an attempt to study the effects of intersubbahd plasmons on the IR optical properties of CLSSLs. As lateral periods of CLSSLs increase from 10 nm to 30 nm, their IR optical properties change from the behavior dominated by single electron transitions between conduction subbands to those dominated by intersubband plasmon excitations. Strong and sharp peaks in the optical absorption coefficients, large variations of the refractive indexes and strong anisotropic optical properties of CLSSLs are predicted in IR regions.     

Uniformly convergent difference schemes for singular perturbation problem

In this paper, a class of uniformly convergent difference schemes for singular perturbation problem are given.     

Phonons and their dispersion in poly(S-benzyl-L-cysteine)

Poly(S-benzyl-L -cysteine) (PBLC) is a S-benzyl derivative of the natural amino acid poly(L -cysteine). Its normal modes and their dispersion in antiparallel β-sheet conformation have been obtained within the first Brillouin zone using Wilson's G.F. matrix method, as modified by Higgs for an infinite polymeric chain. The zone center frequencies and the Urey Bradley force field have been obtained by “best fitting” the observed Fourier transform IR (FTIR) absorption bands. The characteristic features of dispersion curves such as crossing, repulsion, and exchange of character are discussed. Predictive values of heat capacity in the temperature range of 50–500 K are reported. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3269–3287, 1999     

应变对析氢反应催化剂TiC2性能影响的研究

应变工程是一种有效地用来调整原子薄膜材料的电子、磁性和光学性能的策略.利用第一性原理计算,我们表明应变也可以有效地调节Ti C₂的析氢反应(HER)的催化活性,这是电解水电化学制氢所必需的.我们主要考虑0-8%范围的拉伸应变,研究发现,在25%的氢覆盖率下双轴拉伸比单轴拉伸能更有效的提高HER活性,但b方向拉伸后的Ti C₂结构具有更高的氢最大覆盖率,且b方向的拉伸应变对不同氢覆盖率的Ti C₂单层片的催化性能都有很大的提高.电子结构计算表明,拉伸应变可以激活相对惰性的内部价电子,从而引起体系的失稳和催化活性的提高.在本工作中获得的见解可能有助于利用应变作为一种有效手段来提高二维材料的催化活性,并探索更有效地调整其电子结构和催化活性的新方法.     

分布变点模型的非参数检验和区间估计

提 要设　是定义在［０，１］上的随机过程Ｘ（ｔ）的ｎ个等距独立观察值，其中，　服从公共连续分布Ｆ；，服从公共连续分布 Ｆ＊，Ｆ与Ｆ＊不同；其中，是过程 Ｘ（ｔ）的变点．用ＣＵＳＵＭ及Ｂｒｏｗｎｉａｎ Ｓｈｅｅｔ方法给出了检测变点τ位置的一个程序，并证明了所得结果是强相合的；同时也讨论了τ的假设检验和区间估计．     

Cell sheet engineering: intelligent polymer patterned surfaces for tissue engineered liver

We describe a new culture system utilizing the temperature-responsive polymer grafted surface for designing of cell position and layered tissue reconstruction. Organizing of the hepatic tissue structure by controlling the culture system, that is patterned co-culture and layered cell sheet co-culture achieved by moving the cultured cells from the culture surface, resulted in regulation of the hepatocyte function. The technique for cell sheet manipulation would promote the liver tissue engineering in quality.     

Analysis of buoyancy assisting and opposing flows of colloidal mixture of titanium oxide,silver, and aluminium oxide nanoparticles with water due to exponentially stretchable surface

Energy is essential for a nation's economic growth. Energy is recognized in contemporary society as being crucial to the development of quality of life and sustainability. The environment transforms/absorbs heat and sunlight in a variety of ways. Some of these transitions lead to the flow of renewable energy sources like wind and biomass. Solar energy has become one of the promising alternative energy sources in the future because to the improvements made to enhance its performance. In this context, the impact of solar radiation on modified nanofluid flow over an exponential stretching sheet is examined. Using the proper similarity transformations, the governing equations for the flow assumptions are reduced to ordinary differential equations. The numerical simulation of these simplified equations is then performed using the Runge-Kutta Fehlberg method and the shooting methodology. With the aid of graphs and tables, the effects of numerous parameters on the involved fields are described. Results reveal that the modified nano liquid shows increased heat transport for opposing flow situation than the assisting flow situation for incremented values of porosity parameter and volume fraction. The modified nanoliquid shows increased heat transport for opposing flow situation with respect to augmented values of radiation parameter.     

Local Functional Law of the Iterated Logarithm for Increments of a Brownian Sheet北大核心CSCD

本文利用Brown单与Brown单增量的大偏差,得到了Brown单与Brown单增量的局部泛函重对数律.     

A novel radial basis Bayesian regularization deep neural network for the Maxwell nanofluid applied on the Buongiorno model

The aim of this work is to provide the numerical solutions of the fluid model by using the stochastic computing paradigms. The linear/exponential stretching sheets on magneto-rotating flow based on the Maxwell nanofluid have been provided using the Buongiorno model with the impacts of uneven heat source/sink, varying thermal conductivity and reactive species. The solutions of this transformed ordinary differential exponential stretching sheet model have been presented using a novel ‘radial basis’ (RB) activation function together with the Bayesian regularization deep neural network (BRDNN), i.e., RB-BRDNN. The deep neural network is presented into two hidden layers, while thirteen and twenty-five numbers of neurons have been used in the first and second layer. A reference dataset is proposed using the Runge-Kutta scheme for the model. The correctness of the stochastic RB-BRDNN procedure is examined through the comparison of proposed and database results, whereas minimal absolute error values provide the accuracy of the scheme. The reliability and competence of the computing RB-BRDNN solver is authenticated using the state transitions, correlation, regression, and error histograms.