A binary approximating method for graspable region determination of biped climbing robots

For a biped pole-climbing robot (BiPCR) with grippers, it is an essential demand to determine the target grasp configuration for climbing and transiting between poles, with the graspable region as a priori knowledge. The graspable region on the target pole is critically important for climbing path planning and motion control. To efficiently compute the graspable region for a BiPCR, we propose a novel binary approximating method in this paper. This method may also be applied to generate the three-dimensional (3-D) workspace of a manipulator with constant orientation. The grasping problem and the concept of graspable region for a BiPCR are first introduced. The binary approximating method and the corresponding algorithms are then presented to generate the graspable region. Additional constraints on a biped climbing robot with five degrees of freedom (DoFs) are presented as a supplement to the algorithm. A series of comprehensive simulations are conducted with the five-DoF and six-DoF climbing robots to verify the effectiveness of the proposed method. Finally, the dexterity of biped climbing robots with different DoFs is discussed.     

Rheological properties of bitumen in water emulsions with added solids

Experimental work was carried out to investigate the rheological properties of bitumen in water emulsions containing solids of different shape and size. The bitumen volumetric concentration was varied up to 60%, solids free basis, and the solids volume fraction (total volume basis) was varied up to 0.2. Irregular-shaped silica sand (average diameter: 9 and 33 μm) and smooth spherical glass beads (average diameter: 27 and 44 μm) were used as the added solids. In the low shear stress range, shear thinning behavior was observed for bitumen in water emulsions. At high shear stress, the viscosity of the emulsions became fairly independent of the shear stress. The addition of solids to the bitumen emulsions increased the mixture viscosity. The addition of irregular-shaped silica sand gave a higher viscosity than a similar addition of the spherical glass beads. The viscosity of the emulsion/solids mixtures was influenced by the solids size as well; the smaller size particles gave a higher viscosity. The addition of solids to the bitumen emulsions also induced shear thickening (dilatancy) behavior at high solids volume fraction. The degree of the shear thickening increased with the oil concentration.     

Rescheduling policies for large-scale task allocation of autonomous straddle carriers under uncertainty at automated container terminals

This paper investigates replanning strategies for container-transportation task allocation of autonomous Straddle Carriers (SC) at automated container terminals. The strategies address the problem of large-scale scheduling in the context of uncertainty (especially uncertainty associated with unexpected events such as the arrival of a new task). Two rescheduling policies–Rescheduling New arrival Jobs (RNJ) policy and Rescheduling Combination of new and unexecuted Jobs (RCJ) policy–are presented and compared for long-term Autonomous SC Scheduling (ASCS) under the uncertainty of new job arrival. The long-term performance of the two rescheduling policies is evaluated using a multi-objective cost function (i.e., the sum of the costs of SC travelling, SC waiting, and delay of finishing high-priority jobs). This evaluation is conducted based on two different ASCS solving algorithms–an exact algorithm (i.e., branch-and-bound with column generation (BBCG) algorithm) and an approximate algorithm (i.e., auction algorithm)–to get the schedule of each short-term planning for the policy. Based on the map of an actual fully-automated container terminal, simulation and comparative results demonstrate the quality advantage of the RCJ policy compared with the RNJ policy for task allocation of autonomous straddle carriers under uncertainty. Long-term testing results also show that although the auction algorithm is much more efficient than the BBCG algorithm for practical applications, it is not effective enough, even when employed by the superior RCJ policy, to achieve high-quality scheduling of autonomous SCs at the container terminals.     

工业含磷废水除磷研究

在常温条件下，以低廉的氯化镁、碳酸氢铵作沉淀剂加入到含磷废水中除磷时，得到的一次处理液因含磷高无法达标排放。本文利用聚合氯化铝（PAC）和聚丙烯酰胺（PAM）作复合混凝剂，对其进行进一步除磷研究，实验研究证明，加入复合混凝剂的效果优于单独使用，并可使处理后的废水达到国家二类水排放标准。     

Pyrolysed carbon supported cobalt porphyrin: a potent catalyst for oxidation of hydrogen sulfide

Pyrolysed carbon supported cobalt porphyrin, an electrocatalyst that is frequently used for oxygen reduction in fuel cells, is evaluated for catalytic oxidation of hydrogen sulfide by dissolved dioxygen. The catalyst performs best after heat treatment at 880 °C_, at pH 8. Analysis of the reaction products reveals that sulfur is the dominant product throughout the investigated pH range 5–10. The catalyst performs much better than powdered activated carbon, granular activated carbon and different other forms of unmodified carbon catalysts. This is as far as we know the first time that heat treated cobalt porphyrins are evaluated for non-electrocatalytic applications.     

压力流化床燃烧煤水混合燃料泵送给料技术在国外的研究进展

压力流化床燃烧技术近二十年来在世界上得到很大发展。煤的湿法给料系统具有比干法输送系统更简单，运行调节更可靠等优点。煤水混合物可泵送的水分在２５％左右，煤的粒度一般为０～６ｍｍ，表现为非牛顿的假塑性流体特性，通过级配来达到一定的稳定性和良好输送性能，且流动阻力低，不用添加剂即可实现泵送，它的应用使压力流化床的燃烧制备和输送系统成本大大降低。     

循环冷却水系统无垢低腐蚀率的技术改进

泸天化公司大氮肥循环冷却水系统投用以来，经优选水稳剂配方、改进加氯方式、增设旁滤池、提高补充水质量等措施，年腐蚀率从0．3366mm降至0．0241mm，换热器运行一年无结垢现象。     

混合材对水泥与减水剂适应性的影响研究

通过对掺高效减水剂水泥净浆流动性及流动性损失的测定试验，研究了3种混合材(粉煤灰、水淬高炉矿渣和沸石)在不同替代率情况下对减水剂作用效果的影响。结果表明：水淬高炉矿渣有利于改善减水剂与水泥的适应性，而掺粉煤灰和沸石(尤其是沸石)则会导致减水剂塑化作用的降低，而且浆体流动性损失也有增大趋势。     

高分子铁盐絮凝剂制备及其应用研究

研究了以废铁屑和工业硫酸亚铁为原料,在常压和加热条件下,用氯酸钾作为氧化剂制取聚合硫酸铁(PFS)的工艺条件,并在PFS制备的基础上,合成了聚磷硫酸铁(PPFS)和聚氯硫酸铁(PFCS)。将所制备的聚铁用于污水处理实验,结果表明:用该方法制备的聚铁絮凝剂对实际水样具有较好的混凝处理效果,且制备工艺简单、速度快,从根本上消除了用NaNO_2催化氧化法制备聚铁对环境造成的二次污染。