北洺河铁矿废水综合处理与回用

介绍了采用高效澄清反应器处理矿山综合废水的工程实例。在加入了无机混凝剂和有机助凝剂的条件下,测定了反应器出水的COD、BOD和SS等。实际结果表明,系统出水水质达标。     

高分子组合芯模在钢筋混凝土空心楼盖的应用

结合国际学校工程实际情况,详细介绍了现浇钢筋混凝土空心楼盖采用高分子组合芯模的施工工艺及相关技术要点,同时对其关键部位控制要点及检查验收作了简要说明,并针对施工中发现的问题提出了相应的处理措施,以指导今后同类工程。     

球阀腔体泄压及排放标准规定的分析

介绍了相关标准对球阀腔体关于过压排放的规定。针对球阀的不同密封结构,分析了阀门腔体泄压及排放的方法。     

MAC finite difference scheme for Stokes equations with damping on non-uniform grids

In this paper, we consider the numerical methods for stationary Stokes equations with damping. The mark and cell(MAC) method has been applied to discretize the problem on non-uniform grids. We establish the LBB condition and the stability for the MAC scheme. Then we obtain the second order super-convergence in L2 norm for both velocity and pressure on non-uniform grids. We also obtain the second order convergence for some terms of H1 norm of the velocity, and the other terms of H1 norm are second order convergence on uniform grids. Numerical experiments using the MAC scheme show agreement of the numerical results with theoretical analysis.     

燃气冷热电三联供分布式能源站在武汉的发展

通过对武汉市电力负荷、天然气资源、城市环境、城市发展等多角度的剖析,结合燃气冷热电三联供分布式能源站的特点,论述了在武汉建设分布式能源站的必要性和可行性。     

A Genomics-Based Model for Prediction of Severe Bioprosthetic Mitral Valve Calcification

Severe bioprosthetic mitral valve calcification is a significant problem in cardiovascular surgery. Unfortunately, clinical markers did not demonstrate efficacy in prediction of severe bioprosthetic mitral valve calcification. Here, we examined whether a genomics-based approach is efficient in predicting the risk of severe bioprosthetic mitral valve calcification. A total of 124 consecutive Russian patients who underwent mitral valve replacement surgery were recruited. We investigated the associations of the inherited variation in innate immunity, lipid metabolism and calcium metabolism genes with severe bioprosthetic mitral valve calcification. Genotyping was conducted utilizing the TaqMan assay. Eight gene polymorphisms were significantly associated with severe bioprosthetic mitral valve calcification and were therefore included into stepwise logistic regression which identified male gender, the T/T genotype of the rs3775073 polymorphism within the TLR6 gene, the C/T genotype of the rs2229238 polymorphism within the IL6R gene, and the A/A genotype of the rs10455872 polymorphism within the LPA gene as independent predictors of severe bioprosthetic mitral valve calcification. The developed genomics-based model had fair predictive value with area under the receiver operating characteristic (ROC) curve of 0.73. In conclusion, our genomics-based approach is efficient for the prediction of severe bioprosthetic mitral valve calcification.     

不同闭合压力下测试时间对岩心导流能力的影响

利用拟三轴岩心夹持器对劈裂岩心进行加压,考察了测试时间对裂缝导流能力的影响。实验表明:随着测试时间的增加,岩心导流能力逐渐降低,60 min之前下降速度较快,60 min之后下降较慢。加压前期,曲线拟合的误差相对较大,随着加压时间的延长,误差逐渐减小。利用拟合公式对加压后期的导流能力进行预测,从而减少实验的工作量。当裂缝处于闭合阶段时,岩石受到压缩,与储层的实际情况相符,此阶段实验结果可用于对储层进行导流能力评价,更真实地反映油藏条件下裂缝导流能力与应力之间的关系。     

A novel adaptive logic for dynamic adaptive streaming over HTTP

In this paper, we propose an estimation method that estimates the throughput of upcoming video segments based on variations in the network throughput observed during the download of previous video segments. Then, we propose a rate-adaptive algorithm for Hypertext Transfer Protocol (HTTP) streaming. The proposed algorithm selects the quality of the video based on the estimated throughput and playback buffer occupancy. The proposed method selects high-quality video segments, while minimizing video quality changes and the risk of playback interruption, improving user’s experience. We evaluate the algorithm for single- and multi-user environments and demonstrate that it performs remarkably well under varying network conditions. Furthermore, we determine that it efficiently utilizes network resources to achieve a high video rate; competing HTTP clients achieve equitable video rates. We also confirm that variations in the playback buffer size and segment duration do not affect the performance of the proposed algorithm.     

40000m~3/h空分设备变负荷操作及过程优化

主要探讨了冶金用制氧机组如何适应炼钢炼铁需求量的不断变化,减少氧气放散。通过对40000 m3/h制氧机组进行变负荷操作以及对操作过程的优化,实现了节能降耗、减少氧气放散的目的。     

A Min–Max multiregulator system with stability analysis for aeroengine propulsion control

Stability analysis is an essential issue in Min–Max multiregulator control strategy for commercial aircraft engines. In this paper, a Min–Max selector scheme along with a stability analysis method is provided for aeroengine propulsion control. It is assumed that the main regulator is a dynamic compensator and the limit regulators are constant gains. The regulators are determined in such a way that the individual control loops are stable. However, due to the switching nature of Min–Max structure, the stability of single loops does not necessarily ensure the overall system stability. In order to analyze the stability of the presented Min–Maxapproach, the architecture of the control system is transformed into the canonical form of Lure’s system and the condition for absolute stability is specified using Multivariable Circle Criterion. The theoretical results can also be applied to investigate the stability of min-only or max-only schemes. Afterwards, using the provided methodology, the global asymptotic stability is proved for the control system of a high bypass two-spool turbofan engine and the performance of the designed Min–Max controller in tracking a desired fan speed and limit protection in fault-free and fault tolerant situations is compared with the well-known Min–Max/SMC approach.