快速热处理下镍对锗单晶电学性能的影响

采用磁控溅射法在n-Ge表面镀镍薄膜,通过改变快速热处理时间研究镍对锗单晶的导电型号、电阻率和少子寿命的影响,以及镍在锗中的扩散行为。结果表明：镍在锗中具有向内扩散和向外扩散两种行为,并以受主状态存在,改变了锗内部的载流子的分布;775℃热处理后,镍受主完全补偿原有的施主,使锗由n型转变为P型,随着热处理时间的增加,电阻率下降,镍受主浓度增加。即使微量的镍就可以使锗的少子寿命直线下降至零点几微秒,这表明镍在锗中会引入深能级。     

Applicability assessment of a real-time PCR assay for the specific detection of bovine,ovine and caprine material in feedstuffs

A TaqMan real-time polymerase chain reaction (PCR) method was developed for specific detection of bovine, ovine and caprine processed animal protein (PAP) in industrial feedstuffs. The method uses species-specific primers and probes targeting short mitochondrial D-loop sequences, and a positive amplification control based on 18S rRNA gene. The applicability of the real-time PCR protocol was assessed through analysis of 126 industrial feed samples that were manufactured to reproduce rendering processes of commercial feeds destined for farmed animals. The assay successfully classified samples as positive or negative according to the ruminant composition, enabling qualitative detection of banned material in feeds at levels as low as 0.1%. Although the method provides quantitative potential, results suggest that the real quantitative capability of the assay is limited by the existing variability in terms of composition and processing treatments of the feeds, which affect the amount and quality of amplifiable DNA.     

A rapid hybrid algorithm for image restoration combining parametric Wiener filtering and wave atom transform

Image restoration refers to removal or minimization of known degradations in an image. This includes de-blurring images degraded by the limitations of sensors or source of captures in addition to noise filtering and correction of geometric distortion due to sensors. There are several classical image restoration methods such as Wiener filtering. To find an estimate of the original image, Wiener filter requires the prior knowledge of the degradation phenomenon, the blurred image and the statistical properties of the noise process. In this work, we propose a new rapid and blind algorithm for image restoration that does not require a priori knowledge of the noise distribution. The degraded image is first de-convoluted in Fourier space by parametric Wiener filtering, and then, it is smoothed by the wave atom transform after setting the threshold to its coefficients. Experiment results are significant and show the efficiency of our algorithm compared with other techniques in use.     

Convolutional neural network based deep conditional random fields for stereo matching

Stereo matching has been studied for many years and is still a challenge problem. The Markov Random Fields (MRF) model and the Conditional Random Fields (CRF) model based methods have achieved good performance recently. Based on these pioneer works, a deep conditional random fields based stereo matching algorithm is proposed in this paper, which draws a connection between the Convolutional Neural Network (CNN) and CRF. The object knowledge is used as a soft constraint, which can effectively improve the depth estimation accuracy. Moreover, we proposed a CNN potential function that learns the potentials of CRF in a CNN framework. The inference of the CRF model is formulated as a Recurrent Neural Network (RNN). A variety of experiments have been conducted on KITTI and Middlebury benchmark. The results show that the proposed algorithm can produce state-of-the-art results and outperform other MRF-based or CRF-based methods.     

Searching proper oligothiophene segment as centre donor moiety for isoindigo-based small molecular photovoltaic materials

Systematic studies on a family of photovoltaic molecules are important for fundamentally understanding the basic principles and the key structural factors that govern their photovoltaic performance. In this work, a series of D²-A-D¹-A-D² type small molecules with isoindigo as acceptor (A), oligothiophene as donor (D¹), and 5-hexyl thiophene as D² were designed, synthesized and studied. The number of thiophene unit in oligothiophene segment is systematically varied from 0 to 4. It has been found this structural parameter have significant influence on their phase transition behaviours, light absorption properties, frontier orbital energy levels, molecular packing structures in both neat and blending films with [6,6]-phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM), charge mobility, phase separation morphology, and as well as photovoltaic performances. The compounds bearing odd number of thiophene unit displayed much better photovoltaic performance than those having even number, while the best performance was given by that having terthiophene as D¹ unit.     

A combined numerical-experiment investigation on the failure of a pressure relief valve in coal liquefaction

In a direct coal liquefaction unit, pressure relief valves locate on the pipeline between the atmospheric and vacuum towers. Failures of the valve components occur frequently owing to the harsh operation conditions. A combined numerical-experiment investigation on the failures of valves is conducted in this paper. The variation of relative erosion rates of WC–Co coating with impact angles, the function of relative particle velocity, and the distribution of particle diameters are obtained from the high-temperature erosion experiments. Furthermore, the erosion mechanism of WC–Co coating under large impact angles is clarified. In the numerical simulation, the evaporation–condensation, particle motion, erosion, and the modified RNG k-ε turbulence models are used to analyze the phase transition and particle erosion in the valves. Results showed that: due to the high pressure drop and convergent–divergent structure of angle valve, the coal-oil slurry flashes as it enters into the valves. The evaporation of liquid oil produces a large amount of vapor oil, and results in a rapid increase in flow velocity. High concentration solid particles, driven by the high-speed stream, tend to erode the inner surface of valves. Severe erosion can be found in the spool of angle valve, downstream bushings at the angle valve and ball valve. The calculation results agree well with actual failure morphologies, verifies the accuracy of the present prediction method.     

聚合物表面分子松弛行为研究进展

聚合物表面的松弛行为是高分子凝聚态物理研究领域中的一个热点问题,位于表面的高分子具有与本体分子截然不同的运动行为特点,从而赋予了高分子表面许多特殊性质,如特殊的环境响应性和表面粘弹性。文中综述了最近二十年关于聚合物表面分子松弛行为的研究进展,包括基于各种表征技术的研究方法、聚合物表面分子松弛行为的特点和影响因素。可以预测,随着新表征技术的开发应用,对聚合物表面分子松弛行为的研究将越来越深入。     

功能性棉型织物服用性能的模糊综合评判

研究功能性棉型织物综合服用性能优劣的模糊评价方法。对几种不同规格的功能性棉型织物的透气量、悬垂系数、折皱回复角、回潮率、透湿量、芯吸高度等性能进行了相关测试,采用模糊数学综合评判方法对测试数据进行处理分析,通过对权系数和标准化值的计算求算出综合评判值,得到了功能性棉型织物综合服用性能优劣的排序。指出:利用此分析过程对织物整体性能进行评估,既兼顾到织物的综合服用性能,又考虑到各性能权重分配上的差异,分析方法简单、合理、可靠,且评判结果较好。     

大豆蛋白纤维双氧水-尿素漂白工艺研究

探讨了有尿素存在下的大豆蛋白纤维双氧水漂白工艺,分析了双氧水、尿素用量、pH值、温度对处理效果的影响。结果表明,双氧水-尿素漂白工艺优于常规工艺。