江铜集团循环经济之路

江西铜业集团公司是一个集采矿、选矿、冶炼、加工于一体的现代化大型企业,自创建以来,不断探索创新,各项工艺、技术日趋成熟。在发展壮大过程中,江铜坚持走循环经济之路,依靠科技生产力和实用的管理手段,从技术和细节入手,持续提高各种矿产资源回收率,树立“资源-产品-再生资源-再生产品”的新经济理念, 充分回收利用生产过程中产生的废气、废渣、废水、余热等,在“做大、做强、做优”企业的前提下,实现了社会效益优、经济效益高、资源使用省的现代企业目标。     

根据物料特性确定闭路磨矿循环负荷

只要利用闭路磨矿流程给料和产品的粒度分布，通过非线性最优化方法估计出模型参数，就可以求出磨矿回路的循环负荷，因而从理论上省略了测定循环负荷的工作量，具有一定的实际意义。     

循环流化床锅炉燃烧系统的融合控制策略

针对盐化工企业中循环流化床锅炉燃烧控制采用常规PID控制导致系统动、静态品质差,提出了一种基于仿人智能的融合控制策略。文中分析了循环流化床锅炉燃烧系统的特性,研究了控制策略及其相应的工程控制算法,通过仿真试验分别给出了采用最优PID与融合控制策略实施控制的数字仿真响应的对比曲线。实验结果表明,该控制策略的鲁棒性强、稳定性好和控制精度高。     

循环冷却水系统浓缩倍数的管理

主要介绍循环水场浓缩倍数管理中存在的问题,通过对存在问题的分析,找出解决问题的办法.同时对提高循环水浓缩倍数所带来的经济效益进行了分析.提出了确保循环水系统浓缩倍数稳定运行的措施.     

Mass transfer in the core-annular and fast fluidization flow regimes of a CFB

In gas-solid reactors, particularly circulating fluidized beds (CFB) it is becoming increasingly more important to be able to predict the conversion and yield of reactant species given the ever rising cost of the reactants and the ever decreasing acceptable level of effluent contaminants. As such, the development and use of predictive models for the reactors is necessary for most processes today. These models all take into account, in some manner, the interphase mass transfer. The model developer, unless equipped with specific experimentally based empirical correlations for the reactor system under consideration, is required to go to the open literature to obtain correlations for the mass transfer coefficient between the solid and gas phases. This is a difficult task at present, since these literature values differ by up to 7 orders of magnitude. The wide variation in the prediction of mass transfer coefficients in the existing literature is credited to flow regime differences that can be identified in the cited literature upon careful inspection.A new theory is developed herein that takes into account the local hydrodynamics. The resulting model is compared with data generated in the NETL cold flow test facility and with values from the literature. The new theory and the experimental data agree quite well, providing a fundamentally based mass transfer model for predictive reactor simulation codes.     

Particle motion in L-valve as observed by positron emission particle tracking

L-valves are widely used in circulating fluidized beds (CFB) to control the solid circulation rate. Positron emission particle tracking (PEPT) is used to view and study the real-time particle motion in the L-valve. The paper presents experimental results of the solid motion and solid flux in the L-valve, G_s, as a function of the superficial injection air velocity, U. Results are compared with earlier work. The size of the L-valve is 4.5 cm I.D. Two different experimental configurations (L-valve discharge in a CFB riser and free discharge) were used. The L-valve flow regime is stable until approximately 6 U / U_mf, with proportionality between solid flux and U / U_mf. At a higher U / U_mf, unsteady fluctuations in the solid flow gradually increase due to cavity formation around the L-valve elbow. Increasing the air flow even further, a maximum flow is reached, corresponding to the maximum discharge rate through the cyclone or hopper apex. PEPT has also confirmed the existence of a dune flow. For the first time, it gives quantitative data of the velocity profile of the dune flow which is governed by two important factors. The first factor is the distance of solids from the base of the L-valve, with solid velocity increasing away from the base. The second factor is the location of solids with respect to the dune, i.e. solid velocity is minimum at the base of the dunes and maximum at the top of the dunes. The average voidage in the L-valve is approximately constant and independent of U.     

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循环注气是提高凝析气藏开发效果及凝析油采收率的有效措施，而循环注气能否使已经存在于地层中的凝析油重新蒸发是人们普遍关注的问题。作者以柯克亚凝析气藏Ｘ４２—Ｘ５１层系为例，对循环注气开采过程中注入气对凝析油的再蒸发作用进行了数值模拟研究，并对Ｘ５１（３）循环注气试验区现场注气后的情况进行了具体分析，得出了凝析气藏循环注气可以使地层中的部分凝析油重新蒸发采出地面的结论。建议当地层压力低于露点压力时，采用保持压力循环注气开采，可提高凝析油的回收率。     

Epithelial-mesenchymal transition contributes to malignant phenotypes of circulating tumor cells derived from gastric cancer

Circulating tumor cells (CTCs) are crucial to tumor metastasis, and they usually undergo epithelial– mesenchymal transition (EMT) in order to disseminate from the primary tumor. However, very little is currently known about the relationship between EMT and malignant phenotypes of CTCs in the context of gastric cancer. Therefore, this study aimed to investigate the contribution of EMT to malignant phenotypes of CTCs derived from gastric cancer cells. We xenografted MKN28 gastric cancer cells pretreated with transforming growth factor-beta 1 (TGFβ-1) into nude mice by intravenous injection. Next, we isolated CTCs from the blood of nude mice by gradient centrifugation and found that CTCs derived from MKN28 cells pretreated with TGFβ-1 had a significantly increased viability and invasion ability compared to MKN28 cells without TGFβ-1 treatment. Immunocytochemical staining showed lower expression of E-cadherin and higher expression of N-cadherin, vimentin, and β-catenin in CTCs derived from MKN28 cells pretreated with TGFβ-1. Furthermore, the expression of Wnt3a, β-catenin, cyclin D1, and c-Myc was significantly higher in CTCs derived from MKN28 cells pretreated with TGFβ-1. Taken together, these findings suggest that TGFβ promotes EMT and malignant phenotypes of gastric cancer cells. Furthermore, the malignant phenotypes of gastric cancer cells induced by TGFβ are maintained in CTCs derived from these cells. Targeting EMT in CTCs is a new approach to the treatment of gastric cancer relapse and metastasis.     

燃用高挥发份、低灰份燃料的循环流化床锅炉设计

在循环流化床锅炉的设计中,根据燃料的燃烧传热特性,针对特定燃料采取合理的措施,进行优化设计.     

供热系统循环水泵运行工况分析和调节

集中供热系统中，循环水泵是热工控制和调节的重要对象，它的运行工况对热网的水力工况起着决定性的作用。利用水泵和管路的性能曲线对水泵的运行工况进行分析和调节的方法，指出了节约电能、减轻水力失调的主要途径。