Bidirectional Label Propagation over Graphs

Graph-Based label propagation algorithms are popular in the state-of-the-art semi-supervised learning research. The key idea underlying this algorithmic family is to enforce labeling consistency between any two examples with a positive similarity. However, negative similarities or dissimilarities are equivalently valuable in practice. To this end, we simultaneously leverage similarities and dissimilarities in our proposed semi-supervised learning algorithm which we term Bidirectional Label Propagation (BLP). Different from previous label propagation mechanisms that proceed along a single direction of graph edges, the BLP algorithm can propagate labels along not only positive but also negative edge directions. By using an initial neighborhood graph and class assignment constraints inherent among the labeled examples, a set of class-specific graphs are learned, which include both positive and negative edges and thus reveal discriminative cues. Over the learned graphs, a convex propagation criterion is carried out to ensure consistent labelings along the positive edges and inconsistent labelings along the negative edges. Experimental evidence discovered in synthetic and real-world datasets validates excellent performance of the proposed BLP algorithm.     

瓷质砖湿坯对流干燥过程的传热传质研究

引用建立于Whitaker的体积平均方程和Darcy定律基础止的多孔介质内部热质传递的等效耦合扩散模型，寻出一组关于液体饱和度、温度和气相压力的新支配方程，应用该方程组对瓷质砖坯体干燥过程进行了数值分析和实验测定。在平均含湿饱和度的变化方面，数值解与实验结果十分吻合。还改变影响坯体干燥过程的一些因素进行计算机模拟计算，通过改变这些因素的大小来考察计算结果，以期获得某些定性或定量的结论，从而用以指导实际生产过程。     

有限元方法在玻璃成形工艺研究的应用

分析了玻璃在熔融状态下的力学性质、弹粘塑性和刚粘塑性本构方程以及玻璃成形的力学特性等,并结合玻璃成形的热力学公式,介绍了对玻璃成形的热力耦合分析的基本原理,还介绍了在玻璃成形过程中玻璃和模具之间的非线性接触、摩擦问题的求解,自动网格重划分技术.为了说明玻璃成形有限元分析的过程,最后介绍了利用三维大变形有限元方法来模拟电视显像管管屏的压制成形过程和饮料瓶吹制成形过程.     

铝系阻燃剂阻燃PP的力学性能研究

将用偶联剂处理的碱式碳酸铝镁加入到聚丙烯中，通过对体系阻燃性、力学性能等研究得出：碱式碳酸铝镁能够对聚丙烯起到良好的阻燃效果，碱式碳酸铝镁的加入提高了聚丙烯的冲击强度，当碱式碳酸铝镁质量分数为23％时，体系的冲击强度最高。研究了偶联荆的用量对体系力学性能的影响，结果表明，随偶联荆用量的增加，体系的拉伸强度降低，冲击强度先升高后降低，当偶联荆质量分数为1．0％时，体系的冲击强度最高。     

甲烷氧化偶联反应制乙烯的研究进展

介绍了近年来甲烷氧化偶联制乙烯(OCM)过程的催化剂、反应机理、动力学及工程放大涉及的反应工艺、反应器等方面的研究进展,对甲烷氧化偶联法和传统裂解法的经济性进行了对比,指出目前甲烷氧化偶联制乙烯工艺的选择性和转化率还较低,因此成本上比裂解制乙烯要高。最后,对催化剂、工程放大、生产流程和分离方案等方面的研究中存在的问题进行了分析。     

Natural fiber composites of high‐temperature thermoplastic polymers: Effects of coupling agents

Our earlier paper (Jana, S.C.; Prieto, A. J Appl Polym Sci 2002, 86, 2159) on the development of natural fiber composites of high‐performance thermoplastic polymers described a new methodology for the manufacturing of composite materials of a high‐temperature thermoplastic polymer, poly(phenylene ether) (PPE) and wood flour, a cellulosic natural filler. A thermosetting epoxy, used as a reactive solvent, reduced the processing temperature of PPE/epoxy blends to well below the decomposition temperature of natural fillers. In addition, the epoxy component, upon polymerization, formed coating layers around the filler particles to provide resistance against moisture diffusion and attacks by acids and alkali. This article describes the results of an investigation on two outstanding issues: (1) the influence of cellulosic wood particles and coupling agents on the speed of epoxy curing and reaction‐induced phase separation and (2) the effects of coupling agents on the morphology of crosslinked epoxy at the surfaces of natural fillers and mechanical properties of the composites. It was found that wood particles expedited epoxy curing in the composites; the extent of epoxy curing, however, was reduced in the presence of coupling agents. Also, the coupling agents promoted complete coverage of wood flour particles by polymerized epoxy, although the mechanical properties deteriorated over systems without coupling agents. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2168–2173, 2002     

Transient and isotopic studies of the oxygen transport and exchange during oxidative coupling of methane on Sr promoted La2O3

Isotopic transient techniques were applied to study oxidative coupling of methane over lanthanum oxide and strontium promoted La₂O₃ catalysts. Results of the¹⁸O₂/¹⁶O₂ isotopic exchange experiments indicate that Sr promotion increases oxygen uptake from the lattice of the catalyst. Oxygen self diffusion coefficients, which were determined for the series of lanthana catalysts, reach a maximum for the 1% Sr/La₂O₃. Steps of¹⁸O₂ in the presence of a steady flow of methane over Sr/La₂O₃ catalysts, indicate that surface and bulk oxygen appear in the reaction products before gas-phase¹⁸O². Steps of CO₂ over catalysts in which lattice oxygen has been exchanged with¹⁸O₂, show that gas/solid exchange involves over 50% of the lattice oxygen. Under reaction conditions, methane pulses with no gas-phase oxygen yield negligible amounts of products which indicates that methane interacts with lattice oxygen only in the presence of the gas-phase oxygen.     

Wood‐fiber/high‐density‐polyethylene composites: Coupling agent performance

The coupling efficiency of seven coupling agents in wood–polymer composites (WPC) was investigated in this study. The improvement on the interfacial bonding strength, flexural modulus, and other mechanical properties of the resultant wood fiber/high‐density polyethylene (HDPE) composites was mainly related to the coupling agent type, function groups, molecular weight, concentration, and chain structure. As a coupling agent, maleated polyethylene (MAPE) had a better performance in WPC than oxidized polyethylene (OPE) and pure polyethylene (PPE) because of its stronger interfacial bonding. A combination of the acid number, molecular weight, and concentration of coupling agents had a significant effect on the interfacial bonding in WPC. The coupling agents with a high molecular weight, moderate acid number, and low concentration level were preferred to improve interfacial adhesion in WPC. The backbone structure of coupling agents also affected the interfacial bonding strength. Compared with the untreated composites, modified composites improved the interfacial bonding strength by 140% on maximum and the flexural storage modulus by 29%. According to the statistical analysis, 226D and 100D were the best of the seven coupling agents. The coupling agent performance was illustrated with the brush, switch, and amorphous structures. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 93–102, 2005     

水平井分段均衡开采工艺管柱的研制

针对水平井开采过程中水平段动用不均衡的问题,开展水平井分段均衡开采工艺技术研究。详述水平井分段均衡开采工艺技术的设计思路、结构原理,以及技术的核心配套工具——分流装置的工作原理、室内实验等。该技术通过分采泵配合分流器shunt、插封分流开关、双向皮碗封隔器等组合成水平井分段均衡开采工艺管柱,通过选用不同型号分采泵、控制进泵前不同水平段油流通道,实现了对上下两水平段的均衡开采,充分发挥各水平段的潜力。     

惯性往复振动机械阻尼值设计的理论研究

建立了双旋转偏重激振的惯性往复振动机械的状态方程,将该状态方程与两驱动电机的状态方程一起组成机电耦合系统的数学模型,对不同阻尼的机电耦合数学模型进行数值求解,得到不同阻尼时系统的瞬态和稳态解.通过综合分析系统阻尼对最大共振振幅、启动时间、稳态功率消耗及阻尼力的影响,提出了惯性往复振动机械阻尼率的合理设计值为0.1左右.