煤微观结构的X射线衍射原子分布函数分析

采用在非晶态结构研究中应用的Ｘ射线衍射原子分布函数法测试了四种不同煤化程度煤的碳原子平均径向分布，求出了碳原子间距、配位数、芳香度、聚合度和短程有序畴等结构信息，并与文献值进行了以比。结果表明，煤的碳原子间距及对应的配位数介于石墨和金刚石对应的数值之间，随着煤化程度的增加，芳香胺、聚合度和短程有序畴增大，煤的石墨化程度增加。     

A one-step procedure for facile, selective synthesis of protected d-glucopyranosides with free 2-C hydroxyl group starting from peracetylated β-D-glucopyranose

An important field in carbohydrate chemistry is to look for regioselective re-actions of saccharides to simplify the chemical synthesis of oligosaccharides. Oneof such efforts nowadays is directed to the convenient preparation of protected D-     

船型体煤粉燃烧器流场的数值模拟

本文将贴体坐标用于具有复杂形状的船型体煤粉燃烧器的三维流场数值模拟中，建立了在贴体坐标下的总体质量校正方程。计算结果令人满意。同时，对存在的问题作了进一步讨论。     

Effect of the ultrasonic standing wave frequency on the attractive mineralization for fine coal particle flotation

Froth flotation for mineral beneficiation is one of the most important separation techniques; however, it has several challenges for processing fine and ultrafine particles. Attractive mineralization between particles and bubbles by ultrasonic standing wave (USW) is a novel and high-efficiency method that could assist fine particle flotation. Frequency is an important ultrasound parameter, whose effectiveness mechanisms on the attractive mineralization did not compressively address. This study explored the effect of the USW field with various frequencies on the fine coal flotation for filling this gap. Herein, a high-speed camera and a focused beam reflectance measurement (FBRM) were used to analyze three sub-processes of the attractive mineralization, including the microbubbles’ formation, the conventional flotation bubbles (CFBs)’ dispersion, and the particles’ movement. It was found that the maximum flotation metallurgical responses were obtained under the highest examined USW frequency (600 kHz). However, the flotation outcomes by a low USW frequency (50 kHz) were even lower than the conventional flotation tests. Observation and theoretical calculation results revealed these results were originated from the influence of frequency on the carrier bubbles’ formation and the action of the secondary acoustic force during USW-assisted flotation. These outcomes demonstrated that frequency is a key factor determining the success of attractive mineralization for fine particles’ flotation.     

Symmetry protected topological phases in spin-1 ladders and their phase transitions

We study two-legged spin-1 ladder systems with D₂×σ$D_2\times \sigma$ symmetry group, where D₂$D_2$ is discrete spin rotational symmetry and σ$\sigma$ means interchain reflection symmetry. The system has one trivial phase and seven nontrivial symmetry protected topological (SPT) phases. We construct Hamiltonians to realize all of these SPT phases and study the phase transitions between them. Our numerical results indicate that there is no direct continuous transition between any two SPT phases we studied. We interpret our results via topological nonlinear sigma model effective field theory, and further conjecture that generally there is no direct continuous transition between two SPT phases in one dimension if the symmetry group is discrete at all length scales.     

火电厂一次风速及煤粉浓度的数据采集系统设计

探讨用于火电厂一次风管道风速及煤粉浓度在线监测系统的高速数据采集方法与相应的实现技术,可为一次风速及煤粉浓度的测量提供可靠的数据。根据要检测的电厂锅炉一次风管道气固两相流的特性,在基于微波法测量一次风速及煤粉浓度方案的基础上,设计了用于一次风速及煤粉浓度检测的数据采集系统。该采集系统使用ST公司的Cortex M4核心的ARM处理器和高精度、双极性、多路同步ADC采集转换器,并使用百兆以太网通信芯片把采集的数据传送到上位机。实现了四路同步数据的采集、传输及存储,经试验验证,能够稳定的进行数据采集。只需对该系统稍加改动,即可实现8通道同步采集。适用于多数数据采集的场合,具有很好的应用前景。     

开采覆岩破坏工程地质预测的理论与实践

煤层开采造成的覆岩破坏范围和高度是水体下采煤留设防水煤岩柱和老采空区基岩稳定性评价的重要依据，本文以岩体工程地质力学为理论依据，对覆岩破坏机理和判据等进行了研究，详细分析了覆岩工程地质类型及其组合、岩体结构特征、地层倾角、地质构造、地应力、地下水及开采条件对覆岩破坏高度及发育规律的影响。文中提出了覆岩破坏预测的工程地质学方法，并给出了应用实例。     

经酸洗和碱洗处理的伊犁煤焦油的光谱学分析

煤焦油中所含杂质,尤其是不溶物或交联结构极易造成煤焦油深加工设备的堵塞,从而影响煤焦油加工产品的质量.对煤焦油进行净化处理,脱除其所含原生杂质有利于深加工工艺的平稳运行.为此,对新疆伊犁地区产中温煤焦油分别进行酸洗和碱洗处理,以除去煤焦油的部分不溶组分、净化其组成;同时采用核磁共振谱仪和红外光谱仪研究了经酸洗、碱洗处理前后煤焦油相关结构参数的变化.结果表明,分别经酸洗、碱洗处理后,煤焦油的芳碳率均明显减小,而脂碳率相对增加;且碱处理后脂碳率的增加更为显著.经酸洗处理后,焦油芳烃化合物中的缩合芳香核上连接的烷基侧链明显减少,烷氧基发生部分转化或降解,羧基或羰基部分相对含量有所增加,而碱处理后羧基或羰基部分相对含量增加值较为显著.就煤焦油复杂成分的净化而言,碱洗处理效果更好.     

Identification of individual isotopes in a polymer blend using tip enhanced Raman spectroscopy

For the first time, tip enhanced Raman spectroscopy (TERS) blinking measurements are used to identify the individual isotopes of non‐Raman resonant polystyrene in a miscible, binary blend. This demonstrates the sensitivity and selectivity required for nanoscale chemical imaging and broadens the types of surface components potentially identifiable with TERS. Copyright © 2015 John Wiley & Sons, Ltd.     

煤基和石油基C7-沥青质的结构特征及缔合行为

采用核磁(NMR)、小角散射分析(SAXS)、X射线光电子能谱(XPS)、改进的B-L法等手段,研究了煤基C7-沥青质(CT-asp)和石油基C7-沥青质(M-asp)两类沥青质的化学组成、官能团和分子结构等组成结构特征以及差异性,进而通过极性溶剂中沥青质稳定参数研究两类沥青质的缔合行为和聚集体尺寸以及两者之间的氢键和酸碱作用。结果表明,CT-asp分子芳香环数较少且有较多短烷基侧链,且芳香度较高,较高含量氧杂原子以芳香醚和酚羟基赋存形态为主;而M-asp的芳香核尺寸和平均相对分子质量明显高于CT-asp,芳香环数虽较多且有较多长烷基支链,且芳香度较小;两类沥青质缔合聚集程度关联物质的量比(n_(CT-asp)/n_(M-asp))及其分子结构特征,源于杂原子官能团的氢键和酸碱作用是两类沥青质缔合的主要作用力。