A generalized method for correcting instrument spreading in gel permeation chromatography

A general method of chromatogram correction for skewed instrument spreading in gel permeation chromatography is presented. The correction method is so general that there is no restriction on the shape of the spreading function. It admits nonsymmetric, non-Gaussian as well as nonconvolution type. Aspects of solution techniques are discussed and an illustrative example is given to elucidate the method.     

Studies on multilayer film coextrusion III. The rheology of blown film coextrusion

Multilayer blown film coextrusion was studied, both experimentally and theoretically. For the experimental study, an annular die with a feed-port system was designed and multilayer blown films were produced by rotating the inner mandrel with a one horsepower variable-speed drive at speeds from nearly 2 to 6 rpm, and by inflating the tubular molten film with air. The die has 16 feed slots and melt pressure transducers are mounted along the axial direction of the outer wall of the annular flow channel. The transducers were used to determine the pressure gradient in the annular flow channel, which then permitted determination of the reduction in pressure drop when different combinations of two polymer systems were coextruded. Polymers used for b own film coextrusion were: (1) low-density polyethylene with ethylene-vinyl acetate; (2) low-density polyethylene with high-density polyethylene; (3) low-density polyethylene with polypropylene; (4) high-density polyethylene with ethylene-vinyl acetate. For the theoretical study, stratified helical flow was analyzed using a power-law non-Newtonian model. A computational procedure was developed to predict the number of layers, layer thickness, and the volumetric flow rate as functions of certain processing variables (namely, the pressure drop in the die, and the angular speed of rotation of the inner mandrel of the die) and the rheological parameters of the individual polymers concerned. Comparison was made of the theoretical prediction of volumetric flow rate with experimental ones. Some representative results are presented of the theoretically predicted axial and angular velocity distributions, shear stress profiles, and shear rate profiles.     

宽温耐硫变换催化剂制备工艺研究

利用催化剂活性评价、催化剂活性组分含量测定、Ｘ—光衍射等手段，研究了共浸法制备宽温耐硫变换催化剂制备工艺过程中载体氧化铝的吸水率、浸渍条件、煅烧温度等对催化剂性能的影响。     

A DNA-based data hiding technique with low modification rates

In 2010, Shiu et al. proposed three DNA-based reversible data hiding schemes with high embedding capacity. However, their schemes were not focused on DNA modification rate or the expansion problem. Therefore, we propose a novel reversible data hiding scheme based on histogram technique to solve the weaknesses of Shiu et al.’s schemes. The proposed scheme transforms the DNA sequence into a binary string and then combines several bits into a decimal integer. These decimal integers are used to generate a histogram. Afterwards, the proposed scheme uses a histogram technique to embed secret data. The experimental results show that the modification rate of our proposed scheme is 69 % lower than that of Shiu et al.’s schemes for the same embedding capacity. In addition, the length of the DNA sequence remains unchanged in the proposed scheme.     

Intelligent healthcare service based on context inference using smart device

In the field of “U-Healthcare Service”, many studies have been actively conducted to develop “smart device”-based healthcare applications that enable healthcare providers and patients to be better served through interoperations among various kinds of sensors and wireless network interfaces. In particular, contemporary intelligent healthcare services not only recognize users’ context information through smart devices, computers, and so forth, but also acquire information from heterogeneous sensors to achieve context-aware inference services. Among such information, the weather information is tightly related to diseases such as asthma and allergies. Therefore, there is a high demand for research to utilize the weather information for healthcare services. In this paper, we propose a context inference-based intelligent healthcare service that exploits both the weather conditions information and the diverse healthcare ontologies available on the Internet. The proposed service aims at modeling a context ontology in users’ healthcare service environment and defining the inference rules, thereby accomplishing a satisfactory real-time healthcare service.     

Strain-Induced Deformation in Magnesia–Alumina Layered Composites

Ceramic beams are induced in situ to form complex shapes at elevated temperature without the application of an external stress. This process has been demonstrated for thin alumina substrates coated with a layer of magnesia. The internal strain causing the substrates to deform at elevated temperature arises as a consequence of strain mismatch accompanying the penetration of the coating into the substrate. The magnitude of the deformation depends on the amount of coating applied, on the thickness of the substrate, on the density of the substrate, and on the temperature. During exposure of the beams to elevated temperature, the magnesia coating reacts with the alumina substrate to form the spinel phase; the resulting volume change accompanying the phase transformation is likely the predominant driving force for deformation.     

活性污泥法处理污水两个重要参数的理论探讨

负荷、泥龄是活性污泥法处理城市污水设计、运行中的重要参数.给出了有机负荷的动力学表达形式(称之为动力学负荷),并对有机负荷和泥龄的关系,有机负荷和泥龄对水质、污泥沉降性能影响进行了理论探讨.     

基于云计算技术的专利云系统

首先对专利云提出和实施背景进行介绍,在充分调研并借鉴国内外电子商务平台设计和运营模式的基础上,结合专利云平台实施目标,对云平台总体架构进行设计,然后介绍基础平台建设思路和专利云基础软件建设思路,最后,在此基础上设计适合专利云平台的应用软件系统,包括专利公共服务云、专利托管服务云、专利商务交易云三个应用系统.     

MEMS陀螺主要性能指标研究

以ADI公司的微角速度单轴陀螺仪ADXRSXXX为例,对MEMS陀螺的主要性能指标进行了研究,并进行了标定实验,计算了主要性能指标。通过数据拟合方法得到了该陀螺的校准曲线,经过分析计算,该陀螺的精度较高,在姿态测试系统中有一定的应用前景。     

Crystallization studies of semi-crystalline polymers under oscillatory shear using the rheometrics mechanical spectrometer

A method has been developed on the Rheometrics mechanical spectrometer using the eccentric rotating disks mode to study the crystallization kinetics of different semi-crystalline polymers (polyethylene, polypropylene, poly(butylene terephthalate) and Nylon 11) under oscillatory shear. Dynamic shear moduli (storage G′ and loss G″), loss tangent (tan δ), and dynamic viscosity (η′) were simultaneously, monitored during the crystallization process. The onset and completion of crystallization were characterized by the initial rise and final levelling off of G′, while the peak time, of crystallization (t_p) is calculated from the time elapsed between the onset and peak of crystallization which is indicated by the G″ or η′ maximum. In the case of polypropylene, going from a low frequency of ?0.1 rad/s, to higher frequencies of up to 10 rad/s, there is a monotonic decrease in peak time of crystallization (t_p) together with a progressive decrease in spherulitic morphology. The observed acceleration in crystallization is due predominantly to the increase in nucleation rate and orientation of chains in melt crystalline aggregate. The progressive disappearance of the spherulitic morphology is attributed to the disruption of the spherulite superstructure at higher frequencies of shear.