马钢4号高炉中心塌料的原因及处理

对马钢4号高炉中心塌料的原因及处理进行了总结。由于高炉采用中心加焦的布料模式,原燃料质量变差直接导致了高炉中心气流受阻,炉内压差持续升高,出现中心塌料。通过压差控制、布料控制、炉型控制,及送风制度和热制度的管理与调整,在较短时间内,使高炉恢复了正常。认为当原燃料条件变差影响炉况时,调整布料模式的效果有限,应当及时降低冶强、退负荷处理,确保高炉气流稳定,避免高炉操作炉型变化导致炉况失常。

高炉炼铁过程中的对称观

高炉设备内在的对称属性以及炉内炉料层状下降的顺行需求决定了高炉煤气流在圆周方向上必须要对称分布,操作上要讲究参数对称和能力对称。高炉生产过程中的主要问题是高炉内在要求的要素对称性与实际工业生产过程中非对称现象之间的矛盾,高炉炼铁过程中普遍存在非对称现象,对称是相对的,非对称是绝对的;高炉日常操作过程中对炉况的调剂其实质内容就是对高炉对称关系的调节,以促使高炉内各要素保持最大程度的对称状态。高炉顺行状态越好,表明高炉内在各要素的对称性保持越好,掌握高炉对称性的调节对维护高炉长期顺行十分有利。

研山铁矿高压辊磨机工艺参数优化试验

司家营研山铁矿引进高压辊磨机后,其产品指标一直未达到设计要求,为此,对高压辊磨机进行了工业试验,结果表明:在高压辊磨机工作压力为12.5 MPa、边料返回量为70%、辊面线速度为1.78 m/s、给料粒度为+12-40 mm时高压辊磨机破碎效果最佳。

周转箱管理(CMC)项目在上海通用汽车的实施

研究周转箱管理方式在零部件入厂物流方面的应用,分析实施周转箱管理项目的原因和可能性,提出了总体设计规划思路和具体实施、推广方法,提供了具体的流程、步骤、框图和实例,并就项目的持续优化进行了分析。实现了通过科学地强化对入厂物流的控制和管理,既控制了零部件的物流运行风险,又降低约20%的周转箱投入成本。

Endoscopic management of occluded biliary uncovered metal stents:A multicenter experience

AIM:To compare diverse endoscopic interventions in the management of occluded uncovered self-expanding metal stents(SEMSs) that had been placed for palliative treatment of unresectable malignant biliary obstruction.METHODS:A retrospective review was undertaken in 4 tertiary endoscopic centers to determine optimal management of different types of occluded SEMSs.The technical success of performed treatment in occluded SEMSs,the patency of the stent,the need for re-intervention and the financial costs of each treatment were analyzed.RESULTS:Fifty four patients were included in the analysis;21 received Hanaro,19 Wallstent and 14 Flexus.For the relief of obstruction,a plastic stent was inserted in 24 patients,a second SEMS in 25 and mechanical cleaning was performed in 5 patients.The overall median second patency rates between second SEMSs and plastic stents did not differ(133 d for SEMSs vs 106 d for plastic stents;P = 0.856).Similarly,no difference was found between the overall survival of SEMS and plastic stent groups,and no procedure-related complications occurred.Incremental cost analysis showed that successive plastic stenting was a cost-saving strategy at least in Greece.CONCLUSION:Insertion of uncovered SEMSs or plastic stents is a safe and effective treatment for occluded uncovered SEMSs;insertion of plastic stents appears to be the most cost-effective strategy.

新型高产节能粉煤灰烘干机技术

因粉煤灰湿度大、水分高和颗粒细且轻的特质,不易被烘干而大大制约了其利用。南京苏材水泥技术工程有限公司研发了新型高产节能粉煤灰烘干机并已成功投运。文章介绍了该机集供热、烘干、收尘为一体,并采用顺流工艺的技术特点,并就其结构特点和核心创新技术(采用传动齿轮镶嵌式结构,分段组合烘干,加装中心X型扬料板,XLH型烘干机专用反吹钢结构除尘器等)进行了详细分析介绍。四川某公司配置的Ф2.2m×16m新型高产节能粉煤灰烘干机的应用效果为:产量20t/h,初水分17%～18%,终水分1%～2%,系统运行稳定。

An Experimental Study on Distribution of Vertical Stress in a Silo with a Central Inner Downcomer

The distribution of vertical stress for both active and passive state in the silo with a central innerdowncomer is reported in this paper. Experimental measurement of the axial distribution of vertical stress for bothactive and passive state in the silo are in good agreement with that predicted by theoretical analysis. The meanaxial stress is reduced due to the presence of the inner downcomer in the silo.

On Deciding Sustainable Distribution Center of a Supply Chain

A supply chain is a network that performs the procurement of raw material, the transportation of raw material to intermediate and end products, and the distribution of end products to retailers or customers. Installation and operation of distribution centers and all downstream members play a vital role in fulfilling the customers demand and have a great impact for supply chain management performance. In this paper we address a new approach for solving a supply chain optimization model to decide distribution centers based on environmental consideration.

Management of patients with severe traumatic brain injury guided by intraventricular intracranial pressure monitoring： a report of 136 cases

Objective： To evaluate the effect of the treatment modality guided by intraventricular intracranial pressure （ICP） monitoring on patients with severe traumatic brain injury （TBI）. Methods： The clinical data of a group of 136 severely brain-injured patients admitted to Shanghai Neurosurgical Emergency Center from December 2004 to February 2006 were studied. Results： The intraventricular ICP monitor was placed in all the 136 patients via Kocher＇s pathway, Paine＇s pathway or intraoperative opened ventricle. In this series, the probe was placed during the procedure of craniotomy in 98 patients; for other 38 patients, the probe was placed initially to measure or to monitor ICE A stepwise protocol targeting at ICP control （420 mm Hg） and optimal cerebral perfusion pressure （CPP） maintenance （60-90 mm Hg） was deployed.Among them, 76 patients survived with good recovery, 14 with moderate disability, 24 with severe disability, 10 with vegetative state, and 12 died. Complications associated with intraventricular ICP monitoring included hemorrhage and infection. Hemorrhage occurred in 1 patient and infection in 5 patients. There were no unacceptable complications related to ICP monitoring. Conclusions： Ventricular access for 1CP monitoring can be safely and accurately achieved. ICP monitoring via ventriculostomy may facilitate an early and accurate intervention for severely brain-injured patients. The intraventricular ICP monitoring is a low-risk procedure and can yield great benefits for management of patients with severe TBI.

Progress in small-molecule luminescent materials for organic light-emitting diodes

Organic light-emitting diodes （OLEDs） have been extensively studied since the first efficient device based on small molecular luminescent materials was reported by Tang. Organic electroluminescent material, one of the centerpieces of OLEDs, has been the focus of studies by many material scientists. To obtain high luminosity and to keep material costs low, a few remarkable design concepts have been developed. Aggregation-induced emission （AIE） materials were invented to overcome the common fluorescence-quenching problem, and cross-dipole stacking of fluorescent molecules was shown to be an effective method to get high solid-state luminescence. To exceed the limit of internal quantum efficiency of conventional fluorescent materials, phosphorescent materials were successfully applied in highly efficient electroluminescent devices. Most recently, delayed flu- orescent materials via reverse-intersystem crossing （RISC） from triplet to singlet and the ＂hot exciton＂ materials based on hy- bridized local and charge-transfer （HLCT） states were developed to he a new generation of low-cost luminescent materials as efficient as phosphorescent materials. In terms of the device-fabrication process, solution-processible small molecular lumi- nescent materials possess the advantages of high purity （vs. polymers） and low procession cost （vs. vacuum deposition）, which are garnering them increasing attention. Herein, we review the progress of the development of small-molecule luminescent materials with different design concepts and features, and also briefly examine future development tendencies of luminescent materials.

Defect tolerance in chalcogenide perovskite photovoltaic material BaZrS_(3)

Chalcogenide perovskites(CPs) exhibiting lower band gaps than oxide perovskites and higher stability than halide perovskites are promising materials for photovoltaic and optoelectronic applications. For such applications, the absence of deep defect levels serving as recombination centers(dubbed defect tolerance) is a highly desirable property. Here,using density functional theory(DFT) calculations, we study the intrinsic defects in BaZrS_(3), a representative CP material.We compare Hubbard-U and hybrid functional methods, both of which have been widely used in addressing the band gap problem of semi-local functionals in DFT. We find that tuning the U value to obtain experimental bulk band gap and then using the obtained U value for defect calculations may result in over-localization of defect states. In the hybrid functional calculation, the band gap of BaZrS_(3)can be accurately obtained. We observe the formation of small S-atom clusters in both methods, which tend to self-passivate the defects from forming mid-gap levels. Even though in the hybrid functional calculations several relatively deep defects are observed, all of them exhibit too high formation energy to play a significant role if the materials are prepared under thermal equilibrium.BaZrS_(3)is thus expected to exhibit sufficient defect tolerance promising for photovoltaic and optoelectronic applications.

Upper ocean response to tropical cyclone wind forcing: A case study of typhoon Rammasun(2008)

The characteristics of the upper ocean response to tropical cyclone wind （TCW） forcing in the northwestern Pacific were in- vestigated using satellite and Argo data, as well as an ocean general circulation model. In particular, a case study was carried out on typhoon Rammasun, which passed through our study area during May 6-13, 2008. It is found that the local response fight under the TCW forcing is characterized by a quick deepening of the surface mixed layer, a strong latent heat loss to the atmosphere, and an intense upwelling near the center of typhoon, leading to a cooling of the oceanic surface layer that persists as a cold wake along the typhoon track. More interestingly, the upper ocean response exhibits a four-layer thermal structure, including a cooling layer near the surface and a warming layer right below, accompanied by another pair of cooling/warming layers in the thermocline. The formation of the surface cooling/warming layers can be readily explained by the strong vertical mixing induced by TCW forcing, while the thermal response in the thermocline is probably a result of the cyclone-driven upwelling and the associated advective processes.