Three‐dimensional color prediction modeling of single‐ and double‐layered woven fabrics

In this research, the three‐dimensional structural and colorimetric modeling of three‐dimensional woven fabrics was conducted for accurate color predictions. One‐hundred forty single‐ and double‐layered woven samples in a wide range of colors were produced. With the consideration of their three‐dimensional structural parameters, three‐dimensional color prediction models, K/S‐, R‐, and L*a*b*‐based models, were developed through the optimization of previous two‐dimensional models which have been reported to be the three most accurate models for single‐layered woven structures. The accuracy of the new three‐dimensional models was evaluated by calculating the color differences ΔL*, ΔC*, Δh°, and ΔE_CMC(2:1) between the measured and the predicted colors of the samples, and then the error values were compared to those of the two‐dimensional models. As a result, there has been an overall improvement in color predictions of all models with a decrease in ΔE_CMC(2:1) from 10.30 to 5.25 units on average after the three‐dimensional modeling.     

Do funded papers attract more usage?

Research funding has been seen as one of the most important resource in the reward system of science. And usage of publications denotes an interesting perspective of user behavior in scientific communication. This study aims to address the relationship between funding and Usage Count, which is a new metrics item established on the platform of Web of Science. Full records of 300,010 articles published in 2013 were downloaded in October 2015, and divided into six disciplines, including information science library science, education educational research, economics, computer science, materials science, and chemistry. Seven indicators were proposed to measure the impact, including Funding rate, Citation per paper, Usage rate, Usage per paper, Citation difference, Usage difference, and Conversion rate. It concluded funding has impact on usage and citation, and funded papers attract more usage, but varying in different disciplines. Usage Count can be used in the extension of citation metrics but with limits. This study originally engages with usage metrics and detected that there is positive correlation between usage and funding.     

Headspace fingerprinting approach to identify the major pathway influencing volatile patterns of vinasse-cured duck processed by high pressure,as well as its impact on physicochemical and sensory attributes

As a decisive attribute, flavour could be influenced by HP treatments through multiple physical and chemical pathways within the high pressure (HP)-assisted meat curing process. This investigation aimed to identify the major pathway influencing volatile flavour patterns of two representative vinasse-cured duck (VCD) products with HP treatments (150–300 MPa/15 min), including wet and dry types, by employing headspace fingerprinting as an untargeted approach. Results suggested that HP treatments greatly lowered moisture contents and increased Warner-Bratzler shear force and thiobarbituric acid reactive substances of the cured samples. According to multivariate models, the volatile flavour patterns of the HP-processed VCD could be clearly separated from the unprocessed samples, but the VCD pressurised at different intensities represented similar volatile fingerprinting, which was validated by e-nose analysis. The discriminant analysis (OPLS-DA) model outlined vinasse-derived ethanol, acetic acid, 3-methyl-1-butanol, 2-methyl-1-butanol, phenethyl alcohol and 2-methyl-3-octanone as the major discriminant aromas across the unpressurised and pressurised samples.     

大红山铁矿盲小矿体地质勘探技术思路

目前大红山铁矿400万t/a一期采矿工程已接近尾声，现已转入二期工程。随着矿山主矿体的开采，面临着矿石资源量较少、富余人员增多等问题。因此边部盲小矿体开采显得意义更加重大。矿体边部受控矿地质构造的影响，加之前期探矿工程有限，矿体边部盲小矿体未能得到有效控制。通过对大红山井下主矿体边部尤其是南部靠近侵入体边部隐伏盲小矿体特征的分析，实施了“探边扫盲”生产地质勘探工作，为矿山开采提供了资源补充。     

基于旋翼负压混合吸附的爬壁清洗机器人系统动力学性能研究

针对爬壁清洗机器人越障时,负压装置的吸附力下降导致吸附不稳定的问题,设计了一种旋翼负压混合吸附工作的多边形履带清洗机器人,并对爬行稳定性及越障性能进行了动力学分析。首先根据机器人爬壁的运动原理,建立机器人沿玻璃幕墙上的动力学模型,计算出电机理论驱动力矩;其次分析机器人在跨越障碍过程中的运动模型,结合与壁面接触的实际受力状态,对越障过程中关键阶段的本体倾翻、滑移两种失效形式进行运动学和动力学分析;然后根据玻璃幕墙实际的障碍高度,确定多边形履带的参数和理论驱动力矩的大小,并研制了实验样机进行爬行和越障试验,结果表明所设计的机器人具有良好的越障性能。     

基于振动实测的非均质地层钻头失效分析与对策

四川盆地作为国内页岩气开发的重点区域,通过近几年的不断攻关和实践,机械钻速得到了提高,但由于受地层复杂、可钻性差、非均质性强等地质因素的影响,导致井下钻柱系统不良振动剧烈,容易出现钻头损坏严重、钻速较低等问题,严重影响了钻井时效。为了解决上述难题,以该盆地涪陵工区上二叠统龙潭组—中二叠统茅口组为例,采用井下振动高频测量工具的实测手段,测量了钻头—钻柱系统的动态振动加速度参数,结合地层的岩性和矿物组分分析,研究钻头失效原因与对策,并开展了现场试验。研究结果表明:①在非均质地层中钻进的钻头—钻柱系统产生了大于40 m/s~2的高幅值瞬时冲击振动,高幅值的瞬时冲击是导致钻头先期失效的主要原因;②提出了抑制高幅值的瞬时冲击振动采用"减振+增压"工具组合和避免井下工具共振的钻井参数;③采用钻井新参数的试验井比邻井的高幅值瞬时振动降低了17%,单只钻头进尺增加24%,钻头工作环境得到了较大的改善,钻头使用数量减少。结论认为,该研究成果能够有效地改善钻头—钻柱系统的振动状态,有利于达成延长钻头使用寿命的目标。     

In situ polymerization of flame retardant modification polyamide 6,6 with 2-carboxy ethyl (phenyl) phosphinic acid

A novel halogen-free flame retardant copolyamide 6,6 (FR-PA66) was prepared successfully by in situ polymerizing with adipic acid hexamethylene salt and 2-carboxy ethyl (phenyl) phosphinic acid (CEPPA). The elemental composition and chemical structure of FR-PA66 were characterized by energy dispersive X-ray spectroscopy, Fourier transform infrared spectrometer and ¹³C Nuclear magnetic resonance spectrometer. The flame retardancy, thermal stability, and morphology of char residues were also investigated by the limiting oxygen index (LOI), UL 94 test, thermogravimetric analysis, and scanning electron microscopy. The results showed that FR-PA66 samples had much better flame retardancy and char formation ability than pure PA66 after the flame retardant modification. The LOI values were increased from 24.0 to 28.0% by adding 6 wt % of CEPPA and all FR-PA66 samples were rated as V-0 rating in UL-94 test. Furthermore, the thermal stability analysis indicated that in situ polymerization with CEPPA effectively decreased the initial decomposition temperature and increased the amount of char residue. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48687.     

煤气化废水处理工艺探讨

煤气化废水的特点是温度高、硬度高、NH3-N高、有机物含量相对不足。针对这些特点引起的运行不稳定,逐一提出解决方案,并形成一套完整的针对煤气化废水的处理工艺。     

On the performance of band-limited asynchronous DS-CDMA over nakagami-m channels

In this paper we investigated the BER performance of DS-CDMA using various chip-waveforms, which include three time-limited chip-waveforms and two band-limited chip-waveforms. Closed-form formulae were derived for evaluating the achievable bit-error rate performance with the aid of the standard Gaussian approximation, when communicating over a Nakagami-m channel. The time-limited waveforms impose a low implementational complexity, since they maybe over sampled and read from a look-up table. However, they are outperformed by the frequency-domain raised-cosine waveform as well as the optimum waveform specifically designed by Cho and Lehnert for achieving the lowest possible bit error rate