高炉鼓风机风量风压控制系统改造项目的分析与研究

介绍了高炉鼓风机风量风压控制系统改造项目,包括改造目的、改造方案、改造内容、改造的实施过程.分析了改造实施过程中存在的问题,项目技术重点、难点、创新点、技术目标完成情况,并对改造后的经济效益分析及推广应用前景进行了探讨.     

宝钢3号烧结机扩容改造实践

对宝钢3号烧结机扩容改造实践进行了总结。3号烧结机扩容改造的主要内容有:烧结机台车改造、烧结机给料装置改造、尾部罩改造、骨架改造、导料槽改造、单辊破碎机密封罩改造、点火保温炉改造、过程检测与自动控制改造等。3号烧结机通过扩容改造,平均生产率达到32．26t/(m2·d),提产幅度达到14．6％,超过烧结机扩容 10％、产能提高10%的预期目标。     

鞍钢二炼钢厂小方坯连铸机高效化改造

介绍了连铸技术国家工程研究中心对鞍钢二炼钢厂小方坯连铸机实施高效化改造的情况。改造采用了连续锥度结晶器、半板弹簧振动装置、拉矫机的改造、火焰切割等关键技术。说明改造前后机组中主体设备机构特点 ,并阐述了小方坯连铸机改造的投资与效益     

循环氨水泵节能改造

介绍了工厂生产过程中所用泵的节能改造方式,并对切削叶轮节能改造、应用高效水泵或电机、三元流叶轮改造、电机变频调速改造、永磁调速集中改造技术的投资、运行稳定性、维护费用、节能成本等参数进行了对比。中煤旭阳循环氨水泵对泵叶轮进行改造后,节电效果明显。     

宣钢矩形坯连铸机高效化改造

传统连铸机实现高拉速、高质量、高作业率需要实施高效化改造。就宣钢二台矩形坯连铸机实施高效化改造存在的困难进行了论证,介绍了高效化改造应达到的目标,提出了实施高效化的基本思路和技术保证及高效化改造的具体内容,最后计算了与高效化改造有关的技术参数,并把改造前后的生产指标进行了对比分析和经济效益分析。实践证明,高效化改造能给钢厂带来巨大的经济效益,传统连铸机实施高效化改造是钢厂今后节能降耗,结构优化的主要途径之一。     

采用合同能源管理(EMC)模式实施节能改造的实践

简述了合同能源管理模式的概念和特点,以柳钢实施的变频节能改造、水系统节能改造、照明节能改造等介绍了应用合同能源管理模式实施节能改造的效果,并对采用该模式实施节能改造提出建议。     

曲柄式飞剪传动系统技术改造

为适应条钢厂生产的变化则须自主改造飞剪机组。飞剪机组改造应在满足产品工艺变更的需求下,尽可能地减少对主作业线的影响、降低其改造投入。在此原则下,分析计算了原有飞剪机架、剪切机构、齿轮箱体的强度,进行了利旧性改造;对电机、联轴器、飞轮、齿轮副、轴承等进行了新品设计改造。改造后的飞剪机组可满足生产工艺对设备的要求。     

曲柄式飞剪传动系统技术改造

为适应条钢厂生产的变化则须自主改造飞剪机组。飞剪机组改造应在满足产品工艺变更的需求下,尽可能地减少对主作业线的影响、降低其改造投入。在此原则下,分析计算了原有飞剪机架、剪切机构、齿轮箱体的强度,进行了利旧性改造;对电机、联轴器、飞轮、齿轮副、轴承等进行了新品设计改造。改造后的飞剪机组可满足生产工艺对设备的要求。     

浅谈梅山1422mm热轧改造

主要介绍了梅山1422mm热轧带钢轧机改造前的主要问题、热轧改造的过程和主要内容、改造目的以及改造后达到的水平。     

回程式钠离子交换器技术改造

本文详细分析了贵溪冶炼厂动力车间4#、5#钠离子交换器改造前存在的问题,提出了改造方案,介绍了改造后的使用效果,并对改造前后的运行数据、产生的经济效益和社会效益作了对比。     

Tissue preparation in combined scapula flap for microsurgical reconstruction of defects of the oromaxillofacial area]

Nowadays, in congenital or acquired large oro-maxillofacial defects microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aim of reconstruction includes not only restoration of stable continuity and esthetic contour, but also the restoration of a functioning "chewing organ". For reconstruction in maxillary and midface defects, we prefer the scapular flap for a single-step reconstruction. Tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable soft tissue conditions at the time of microsurgical reconstruction. Following dental restoration, full oral function is given. This single-stage procedure improves the psychosocial situation of the patient considerably when compared with conventional multi-stage reconstruction.     

Estimation of Time for Wenchuan Earthquake Reconstruction in China

Time is considered extremely urgent in China’s Wenchuan earthquake reconstruction. However, little research has been undertaken on estimating the time needed for reconstruction in China, especially for this specific reconstruction. Therefore, this paper aims to explore the time-cost relationship for the Wenchuan earthquake reconstruction. Both the Bromilow’s time-cost (BTC) model and the Elman network (EN) model have been developed to predict the time of Wenchuan earthquake reconstruction projects. Data have been obtained from 72 completed construction projects in the six cities that were seriously affected by the major Wenchuan earthquake. The result from the BTC model has been compared with that from the EN model to determine which one is more accurate. The results show that the EN model provides a more accurate time prediction for Wenchuan earthquake reconstruction than the BTC model does, though the BTC model is more suitable for application in practice. It is also shown that the proposed models are both useful for estimating the duration of reconstruction projects.     

Maximum likelihood as a common computational framework in tomotherapy

Tomotherapy is a dose delivery technique using helical or axial intensity modulated beams. One of the strengths of the tomotherapy concept is that it can incorporate a number of processes into a single piece of equipment. These processes include treatment optimization planning, dose reconstruction and kilovoltage/megavoltage image reconstruction. A common computational technique that could be used for all of these processes would be very appealing. The maximum likelihood estimator, originally developed for emission tomography, can serve as a useful tool in imaging and radiotherapy. We believe that this approach can play an important role in the processes of optimization planning, dose reconstruction and kilovoltage and/or megavoltage image reconstruction. These processes involve computations that require comparable physical methods. They are also based on equivalent assumptions, and they have similar mathematical solutions. As a result, the maximum likelihood approach is able to provide a common framework for all three of these computational problems. We will demonstrate how maximum likelihood methods can be applied to optimization planning, dose reconstruction and megavoltage image reconstruction in tomotherapy. Results for planning optimization, dose reconstruction and megavoltage image reconstruction will be presented. Strengths and weaknesses of the methodology are analysed. Future directions for this work are also suggested.     

Clinical study and application of 3DCT in oral and maxillofacial regions

3DCT reconstruction as a new roentgenographic technique has not been used so much in oral and maxillofacial regions in our country. From May 1993 to May 1995, 72 cases of 3DCT reconstruction have been performed by a Siemens Plus-s CT scanner for the maxillofacial injuries and jaw bone diseases. The 3DCT reconstruction of soft tissuses has been used too. It is showed that 3DCT reconstruction is a useful technique for the diagnosis and surgical planning of diseases in oral and maxillofacial regions.     

Using the latissimus dorsi flap for breast reconstruction

The preferred method for breast reconstruction is the simplest type that can meet the patient's needs and expectations (Bostwick, 1989). Several breast reconstruction procedures are presented in this issue. In this article, only breast reconstruction using the latissimus dorsi flap is discussed.     

Classification and identification of propionibacteria based on ribosomal RNA genes and PCR

For appropriate patients, who are aware of and accept the risks involved, contralateral prophylactic mastectomy and bilateral reconstruction can provide a good solution to an otherwise difficult problem. Bilateral reconstruction can produce exceptionally good aesthetic results and, because good symmetry is achieved in the initial surgery, it only costs about 5% more than unilateral reconstruction. This article discusses the techniques, advantages, and disadvantages of bilateral reconstruction.     

Total reconstruction of the posterior wall of the external ear canal with allogenic rib cartilage. Technique and results

Middle-ear reconstruction using a closed surgical technique has the same surgical stages as in combined-approach tympanoplasty. The only special feature is the reconstruction of the posterior canal wall and scutum, an essential step. This reconstruction process is carried out with allogenic costal cartilage affixed to two deep bony slots with fibrin glue. In 90% of cases surgery is done in two stages.     

Analysis of reconstruction procedures for defects of the mouth floor. Report of 96 cases

The aim of this study was to assess the reconstruction of floor of the mouth defects after cancer surgery. The medical records of 140 patients treated between January 1st, 1987 and December 31st, 1995 were reviewed. Ninety-six patients had primary reconstruction: there were 82 cutaneous or osteomyocutaneous flaps and 14 microsurgical transfers. Among these patients 15 had titanium mandibular reconstruction plates. The reconstruction procedures and postoperative follow-up were evaluated. Healing by first intention is appropriate for superficial soft tissue defects. The nasolabial flap is used only for small mucosal defects. A forearm flap should be the first choice treatment for large soft tissue defects owing to its plasticity and reliable vessels. Segmental mandibular resections often imply mandibular reconstruction. Titanium plates may be used alone or with a cutaneous flap. Tolerance of plates after radiotherapy is very good and they are an effective method of reconstruction for fragile patients.     

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using RBSC for fully 3D compensation has resulted in prohibitively long reconstruction times. In this work we propose two new methods that can be used in conjunction with existing methods to achieve marked reductions in RBSC reconstruction times. The first method, coarse-grid scatter modelling, significantly accelerates the scatter model by exploiting the fact that scatter is dominated by low-frequency information. The second method, intermittent RBSC, further accelerates the reconstruction process by limiting the number of iterations during which scatter is modelled. The fast implementations were evaluated using a Monte Carlo simulated experiment of the 3D MCAT phantom with 99mTc tracer, and also using experimentally acquired data with 201Tl tracer. Results indicated that these fast methods can reconstruct, with fully 3D compensation, images very similar to those obtained using standard RBSC methods, and in reconstruction times that are an order of magnitude shorter. Using these methods, fully 3D iterative reconstruction with RBSC can be performed well within the realm of clinically realistic times (under 10 minutes for 64 x 64 x 24 image reconstruction).     

Relapsing polychondritis presented as inner ear involvement

A patient with Buerger's disease is described in whom reconstruction of a gangrenous forefoot with a free flap has been successfully performed. In order to limit the amputation level, a more aggressive approach toward reconstruction in young patients seems appropriate. To our knowledge, this is the first described case of free flap reconstruction of a gangrenous defect in a Buerger patient.