新型阳离子（甲基丙烯酸季铵盐酯－苯乙烯）共聚物的研究──Ⅰ阳离子（甲基丙烯酸二甲氨基乙酯溴代正丁烷盐－苯乙烯）共聚物的合成与表征

甲基丙烯酸Ｎ，Ｎ－二甲氨乙酯（ＤＭＡＥＭＡ）与溴正丁烷在丙酮溶剂中进行季铵化反应，制得甲基丙烯酸季铵盐酯（ＭＢＤＭ）；然后以ＡＩＢＮ为引发刑，ＭＢＤＭ与苯乙烯（Ｓｔ）在溶液中进行自由基共聚，制得阳离子共聚物Ｐ（ＭＢＤＭ－Ｓｔ），其结构用红外光诸法鉴定，并经￣１ＨＮＭＲ和元素分析表征，证实有可能根据δ２．８～４．１和δ７．２２处两个共振峰确定共聚物的组成．     

A power series for vibration of a rotating nanobeam with considering thermal effect

In this article, the equation of motion for a rotating nanocantilever has been developed based on the Euler–Bernoulli beam model, which includes the effect of temperature, small scale effect, and centrifugal force. A power series method has been employed to obtain the exact solution of the natural frequencies. The results also compared with other solutions of exact and approximate differential quadrature method. The effects of temperature, angular velocity, and small scale in the vibration characteristics of a rotating nanocantilever beam are investigated. It is shown that the effect of temperature plays a significant role in the behavior of the vibration of a rotating nanocantilever. Nondimensional frequency increases in the first mode with increasing the nonlocal parameter while it is inverse for the second and third modes of vibration.     

A computer-aided diagnosis system for malignant melanomas

The aim of this study is to provide an efficient way to segment the malignant melanoma images. This method first eliminates extra hair and scales using edge detection; afterward, it deduces a color image into an intensity image and approximately segments the image by intensity thresholding. Some morphological operations are used to focus on an image area where a melanoma boundary potentially exists and then used to localize the boundary in that area. The distributions of texture and a new feature known as AIBQ features in the next step provide a good discrimination of skin lesions to feature extraction. Finally, we rely on quantitative image analysis to measure a series of candidate attributes hoped to contain enough information to differentiate malignant from benign melanomas. The selected features are applied to a support vector machine to classify the melanomas as malignant or benign. By our approach, we obtained 95 % correct classification of malignant or benign melanoma on real melanoma images.     

A new fast algorithm for multiclass hyperspectral image classification with SVM

The support vector machine (SVM) has been a dominant machine-learning technique in the last decade and has demonstrated its efficiency in many applications. Research on classification of hyperspectral images have shown the efficiency of this method to overcome the Hughes phenomenon for classification of such images. A major drawback of classification by SVM is that this classifier was originally developed to solve binary problems, and the algorithms for multiclass problems usually have a high-computational load. In this article, a new and fast method for multiclass problems is proposed. This method has two stages. In the first stage, samples are classified by a maximum likelihood (ML) classifier, and in the second stage, SVM selects the final label of a sample among high-probability classes for that sample by a tree structure. So, for each sample, only some classes must be searched by SVM to find its label. The uncertainty of ML classification for a sample is obtained by the entropy of probabilities, and the number of classes that must be searched by SVM for a sample is obtained based on the uncertainty of that sample in the primary ML classification. This approach is compared with two widely used multiclass algorithms: one-against-one (OAO) and directed acyclic graph (DAGSVM). The obtained results on real data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) revealed less computational time and better accuracy compared to these multiclass algorithms.     

Free vibration analysis of double-viscoelastic nano-composite micro-plates reinforced by FG-SWCNTs based on the third-order shear deformation theory

Microsystem Technologies - In this paper, free vibration analysis of a double viscoelastic nano-composite plate system reinforced by functionally graded single-walled carbon nanotubes (FG-SWCNT)...     

Coupled twist–bending static and dynamic behavior of a curved single-walled carbon nanotube based on nonlocal theory

The static and dynamic behavior of a curved single-walled carbon nanotube which is under twist–bending couple based on nonlocal theory is analyzed. The nonlocal theory is used to model the mechanical behavior of structure in small scale. The obtained differential equations are solved using a simply supported boundary condition and Navier analytical method. Moreover the twisted vibration and bending of curved nanotube is analyzed and also the armchair model is assumed in this study. The following parameters were studied in this paper: the effect of nonlocal parameter, the curved nanotube’s opening angel, the Young’s modulus and the mode number is studied. The results were verified with the previous literature which showed an excellent agreement. The results of this paper can be used as a benchmark for future investigations.

     

Study of connection detailing on SMRF seismic behavior for unequal beam depths

This study investigates the differences in the seismic behavior of Special Moment Resisting Frames (SMRF) with unequal beam depths, which can be affected by connection detailing arrangements. The studied connection detailing arrangements consist of continuity plate arrangements, such as straight or inclined continuity plates, coverplate, flange plate connections, and the haunch connection system on the shallow beam side, which can create some alternatives for the connection of the shallow beam and the deep beam to the column. In spite of the occurrence of this special case in everyday engineering practice, the codes do not take these special cases into consideration. Six full-scale experiments were performed in order to improve the understanding of the seismic behavior associated with this special case. Companion analyses were then conducted in order to consider the effects of the above-mentioned connection detailing arrangements on the analytical rupture indices. The results of the experiments and analyses have shown that the described connection detailing arrangements can achieve performance corresponding to story drift ratios of at least 4% to 6% before experiencing 20% strength degradation. By the use of a specific combination of a flange plate connection with a haunch connection system, crack propagation on the deep beam's bottom flange, which is observed in most connection detailing arrangements for this special case, can be eliminated.     

Electrochemical reduction of nickel ions from diluteartificial solutions in a GBC reactor

The electrochemical reduction of nickel ions from a dilute solution has been carried out in a gas diffusion electrode packed bed electrode cell (GBC). Particle size and electrode configuration have been found to have a significant influence on the reduction process. Electrodes with a high porosity and large pores have been found to be the best for nickel deposition. The nickel current efficiency, Ni, is reported to be dependent on the current density, volumetric flow rate, nickel and boric acid concentration, and the pH. The fall in the nickel current efficiency is caused by an increase in electrode surface pH above a certain level, caused by either high bulk solution pH or high current density, leading to possibly formation of Ni(OH)2. It has been found that under conditions of exclusively metallic nickel deposition Ni/(1–Ni) is proportional to i0.69,Q10.52,CNi0.67,CBA–0.19 and pH1.0.     

Pharmacology and subcellular distribution of [3H]rilmenidine binding sites in rat brain

We have previously reported that in rat brain membranes, [3H]rilmenidine, in addition to labelling alpha2-adrenoceptors and the I2B-subtype of imidazoline receptor binding site (I2B-RBS), may label an additional I-RBS population, distinct from previously classified I1-RBS and I2-RBS. In this study, using crude or fractionated rat brain membranes we examined the possible association of [3H]rilmenidine-labelled I-RBS with the A- and B-isoforms of monoamine oxidase (MAO) by studying the inhibition of [3H]rilmenidine binding by a number of MAO inhibitors; and comparing the maximal binding density (Bmax) and subcellular distribution of [3H]rilmenidine binding sites with that of MAO-A and MAO-B catalytic sites labelled by [3H]RO41-1049 and [3H]RO19-6327 and 12-RBS labelled by [3H]2-BFI. Inhibition of [3H]rilmenidine binding by all MAO inhibitors tested produced very shallow curves (slope 0.29-0.56). Clorgyline and moclobemide (selective MAO-A inhibitors) displayed moderate affinities (60-140 nM), while pargyline (non-selective MAO-inhibitor), RO41-1049 (selective MAO-A inhibitor) and RO19-6327 (selective MAO-B inhibitor) exhibited very low affinities (> 2 microM) for 50-75% of [3H]rilmenidine-labelled I-RBS in crude brain membranes and even lower affinity for the remaining binding. Under identical buffer conditions, the Bmax of [3H]rilmenidine-labelled I-RBS (1.45+/-0.14 pmol/mg protein) was considerably lower than those of MAO-A (13.10+/-0.15 pmol/mg) and MAO-B (10.35+/-0.50 pmol/mg) sites. These results suggest that [3H]rilmenidine does not interact directly with the active catalytic site of either MAO enzyme and could at best only associate with a subpopulation of MAO molecules. Binding studies on five fractions of rat cortex homogenates-nuclear (N), heavy (M) and light (L) mitochondrial, microsomal non-mitochondrial (P), and soluble cytosolic (S) fractions-revealed that 45% of total [3H]rilmenidine binding was present in the P fraction cf. 20 and 23% in the M and L fractions, in contrast to [3H]RO19-6327 and [3H]2-BFI which bound 11-13% in the P fraction and 36-38% and 35-44% in the M and L fractions, respectively. Binding of all ligands in the N fraction was 6-15% of total. These studies reveal that [3H]rilmenidine-labelled I-RBS, unlike the I2-RBS, are not predominantly associated with mitochondrial fractions containing the MAO enzymes (and cytochrome oxidase activity), but appear to be distributed in both the mitochondrial and plasma membrane fractions in rat cerebral cortex.