A Pseudo-document-based Topical N-grams model for short texts

World Wide Web - In recent years, short text topic modeling has drawn considerable attentions from interdisciplinary researchers. Various customized topic models have been proposed to tackle the...     

泊松模型预测吹填土地区路基沉降的应用研究

泊松曲线是一种"S"成长型曲线模型,吹填土路基沉降规律与泊松曲线变化规律极其相似。结合某吹填土工程实例,利用泊松曲线模型对吹填土路基沉降进行预测。对比时间间隔为10,20,30 d的预测效果,结果表明:时间间隔为20 d时,泊松曲线沉降预测模型与实测数据吻合较好,尤其是后期误差在4.5%以下。该模型可以为以后的吹填土路基沉降预测提供有益的参考,甚至其成果可以在以后的工程中运用,有一定的经济、社会效益。     

有机气凝胶动态力学响应规律及防护性能

使用霍普金森压杆对有机气凝胶的动态力学响应规律进行研究,并对有机气凝胶的破坏机理和防护机理及防护性能进行研究。结果表明：有机气凝胶在动态压缩下表现出非常明显的应变率强化效应,吸能大幅增加;在冲击加载过程中有机气凝胶呈现粉碎破坏,胶体粒子发生熔合的现象;有机气凝胶具有较好的抗弹性能和较高的质量防护系数。     

双亲性聚合物调理剂在护发素中的应用研究

研究了双亲性聚合物作为调理剂成分在无硅油护发素中的应用。以溶液自由基聚合法合成了双亲性无规聚合物聚(苯乙烯-co-丙烯酸)。利用阳离子表面活性剂山嵛基三甲基氯化铵与聚合物之间的阳离子-π电子作用,将双亲性无规共聚物聚(苯乙烯-co-丙烯酸)吸附到头发表面起到顺滑作用。通过调节聚合物中苯环与山嵛基三甲基氯化铵的摩尔比、山嵛基三甲基氯化铵的浓度以及使用量,制备具有优异梳理性能的护发素,对护发素效果进行评价,并与含硅护发素进行比较。结果表明:最优条件下,双亲性聚合物在头发上的残留量为102μg/g头发;在护发素中添加双亲聚合物后能够显著改善湿梳理性能,其湿梳性优于市售含硅护发素;经护发素处理后的头发毛鳞片规整、无翘起,且双亲聚合物在头发上无累积效应。     

工程监理对施工安全的控制要点及措施

论述监理工程师必须加强施工安全管理,重点叙述施工安全控制要点、要求及措施。     

TiAl合金激光表面原位TiC颗粒增强涂层及高温抗氧化性能

以高纯石墨粉和C Nb混合粉末为原料,对Ti-46Al-2Cr-1．5Nb-1V合金进行了激光表面合金化处理,对激光改性层的显微组织以及成分进行了观察与分析,并对该合金原始组织及经C和C Nb激光表面改性层的高温抗氧化性能进行了对比分析研究。结果表明,C和C Nb激光表面合金化处理后,在合金表面均“原位”形成了TiC颗粒,Nb以固溶原子形式存在于表面改性层中,TiC颗粒的大小,形态及分布强烈取决于激光工艺参数;激光表面处理后的合金的抗氧化性能明显高于未经激光处理的铸态组织,而且在石墨粉中掺杂Nb粉,处理后的合金具有最佳的抗氧化性能。     

An Improved Protocol for Deadlock and Livelock Avoidance Resource Co-allocation in Network Computing

A multitude of applications require simultaneous access to multiple kinds of resources scatted in distributed sites. This problem is known as resource co-allocation which has evolved as a hot topic in network computing. How to design a kind of high-performance protocol for deadlock and livelock avoidance resource co-allocation becomes a challenging problem. In this paper, we propose a new protocol OODP³ (Optimal ODP³) which is based on the currently popular protocol ODP³ (Order-based Deadlock Prevention Protocol with Parallel requests).OODP³ not only inherits the advantage of ODP³ but also guarantees the fulfillment of resource co-allocation within polynomial time. Theoretical proof is conducted to verify the correctness of OODP³. Experimental results also show that OODP³ achieves the better performance improvements than the existing deadlock and livelock avoidance protocol.     

Existing State and Partitioning of Rare Earth on Weathered Ores

The existing state and partitioning of rare earth （RE） on weathered ores in Longnan County（LN）, Xingfeng County（XF） and Ninghua County（NH） were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases： （a） water soluble, （b） ion-exchangeable, （c） colloidal sediment （oxides）, （d） minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE, with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2 %. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce^3＋ is oxidized into Ce^4＋ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.     

State estimation for complex systems with randomly occurring nonlinearities and randomly missing measurements

This paper is concerned with the state estimation problem for the complex networked systems with randomly occurring nonlinearities and randomly missing measurements. The nonlinearities are included to describe the phenomena of nonlinear disturbances which exist in the network and may occur in a probabilistic way. Considering the fact that probabilistic data missing may occur in the process of information transmission, we introduce the randomly data missing into the sensor measurements. The aim of this paper is to design a state estimator to estimate the true states of the considered complex network through the available output measurements. By using a Lyapunov functional and some stochastic analysis techniques, sufficient criteria are obtained in the form of linear matrix inequalities under which the estimation error dynamics is globally asymptotically stable in the mean square. Furthermore, the state estimator gain is also obtained. Finally, a numerical example is employed to illustrate the effectiveness of the proposed state estimation conditions.