浅析干法选煤技术与设备

在介绍干法选煤技术现状的基础上，着重分析了风力选煤技术和空气重介质流化床干法分选技术的分选原理、分选特点和发展趋势，指出开发系列高效干法选煤技术不仅是提高能源利用效率、减少环境污染的有效途径，也是顺应我国煤炭工业战略西移、发展洁净煤技术的必然要求。     

PVA-clay nanocomposite hydrogels for wound dressing

Polymer gels as soft biomaterials have found diverse applications in biomedical field, e.g. in management and care of wound as wound dressing.The recent researches on nanocomposite materials have shown that some properties of polymers and gels significantly improve by adding organoclay into polymeric matrix. In this work, in order to obtain wound dressing with better properties, nanocomposite hydrogel wound dressing was prepared using combination of polyvinyl alcohol hydogel and organoclay, i.e. Na-montmorillonite, via the freezing-thawing method. The effect of organoclay quantity on the structural, swelling, physical and mechanical properties of nanocomposite hydrogel wound dressing was investigated. The results showed that the nanocomposite hydrogels could meet the essential requirements for the reasonable wound dressing with some desirable characteristics such as relatively good swelling, appreciated vapour transmission rate, excellent barrierity against microbe penetration and mechanical properties. The results also indicated that the quantity of the clay added to the nanocomposite hydrogel is the key factor in obtaining such suitable properties required for wound dressing.     

坚持技术创新走可持续发展道路

通过对选煤各主要环节的工艺设备实施自主式技术改造和大胆革新，使选煤工艺不断优化。产品质量和生产效率不断提高，经济效益不断增长，为企业的可持续发展奠定了技术基础。     

女裤穿着与设计的美学思考

裤装是表现女性自身关的重要手段。穿着时间、穿着场合、自身的身材条件以及职业、性格、经济条件等是女裤美的重要条件。女裤在时尚女装中占有重要位置。     

The signed-graphic representations of wheels and whirls

We characterize all of the ways to represent the wheel matroids and whirl matroids using frame matroids of signed graphs. The characterization of wheels is in terms of topological duality in the projective plane and the characterization of whirls is in terms of topological duality in the annulus.     

超声波探头阵列自动探伤系统设计

描述了由计算机控制探头阵列电扫描对列车轮对探伤工作模式，以取代机械扫描方式。电扫描工作方式可简化机械结构以及减轻探头的机械磨损，尤其是计算机对探伤波形处理和工件缺陷的定位和定性是非常方便的，本文给出了系统结构和程序框图。     

Discrete element method simulations of Mars Exploration Rover wheel performance

Mars Exploration Rovers (MERs) experienced mobility problems during traverses. Three-dimensional discrete element method (DEM) simulations of MER wheel mobility tests for wheel slips of i = 0, 0.1, 0.3, 0.5, 0.7, 0.9, and 0.99 were done to examine high wheel slip mobility to improve the ARTEMIS MER traverse planning tool. Simulations of wheel drawbar pull and sinkage MIT data for i ⩽ 0.5 were used to determine DEM particle packing density (0.62) and contact friction (0.8) to represent the simulant used in mobility tests. The DEM simulations are in good agreement with MIT data for i = 0.5 and 0.7, with reasonable but less agreement at lower wheel slip. Three mobility stages include low slip (i < 0.3) controlled by soil strength, intermediate slip (i ∼ 0.3–0.6) controlled by residual soil strength, and high slip (i > 0.6) controlled by residual soil strength and wheel sinkage depth. Equilibrium sinkage occurred for i < 0.9, but continuously increased for i = 0.99. Improved DEM simulation accuracy of low-slip mobility can be achieved using polyhedral particles, rather than tri-sphere particles, to represent soil. The DEM simulations of MER wheel mobility can improve ARTEMIS accuracy.     

侧吹气体对光纤激光修锐青铜金刚石砂轮等离子体特性影响

为了研究辅助侧吹氩气对光纤激光修锐青铜结合剂金刚石砂轮等离子体的影响,利用高速摄像机拍摄不同侧吹工艺参数下等离子体空间膨胀形态,结果表明：氩气降低了等离子体的膨胀高度,随着压力增加,等离子体的膨胀距离减小,等离子抑制作用增强。 利用光谱仪研究了等离子体发射光谱在砂轮径向上的最大值随氩气压力的变化情况,并根据Boltzmann斜线法和Stark展宽法,计算不同氩气压力下等离子体在砂轮径向上电子温度和电子数密度的最大值,结果表明：气体压力增大,等离子体光谱线强度先增大后减小,等离子体光谱线强度在0.2 MPa时达到峰值,较大的氩气压力明显降低等离子体电子温度和电子数密度,从而减小对砂轮表面形貌的影响。 利用超景深三维扫描仪观测添加侧吹气体前后砂轮表面形貌,结果表明：0.5 MPa侧吹氩气后,砂轮表面形貌质量明显优于未添加侧吹气体时。     

可注射水凝胶在伤口敷料中的研究进展

目前,在伤口治疗中对伤口敷料的选择越来越严格。传统的伤口敷料如纱布、绷带、海绵等在伤口愈合过程中容易诱发细菌感染,延缓伤口愈合,甚至引发慢性并发症。可注射水凝胶具备良好的生物相容性,能够适应伤口的形状以填充伤口,且具备一定的抗菌活性,从而避免伤口感染,相比传统的水凝胶伤口敷料更具备医疗优势,因此在生物医药领域得到广泛关注。本文对天然型可注射水凝胶和复合型可注射水凝胶在伤口愈合中的研究进展进行了综述;也对可注射水凝胶的未来发展趋势进行了展望。