利用Aspen Plus优化甲乙酮制备工艺

对现有MEK生产工艺进行改进,增加其产量。利用Aspen模拟软件对MEK的工艺流程进行理论计算和模拟,通过用户自定义模块方法,对简化的SBA气化脱氢工艺流程包括反应部分、加盐萃取精馏部分和甲乙酮精制部分进行了全流程稳态模拟。并探讨流程中塔板数、回流比、进料位置和状态对分离效果的影响,提出最优操作参数。通过对MEK工艺的每个阶段进行优化,可确定每个塔的最佳工艺条件以得到最大的甲乙酮产量,并可提高产品的纯度。在最优条件下完成车间整体设计以及最大收益过程的研究。     

Effect of pore characteristics of fine lignite on particle density in separation medium

Effect of porosity on particle density was analyzed, which can be a potential factor of low efficiency. The porosity of particle with different densities was detected by surface area analyzer. In addition, Three-dimensional X-ray micro-imaging system (3D-XRM) was used to analyze the spatial distribution of internal pores. Results show that mesoporous and microporosity content increase with the increase of particle density. Three-dimensional distribution of pores shows that the pores are very rich and show a good connection. The density model including porosity and medium density was established, which shows the effect of medium filling on the change of particle density.     

Study of tritium transport characteristics in a transportable fluoride‐salt‐cooled high‐temperature reactor

Tritium management is one of the most critical issues that limit the development of fluoride‐salt‐cooled high‐temperature reactor (FHR); therefore, it is important to figure out the tritium transport characteristics in FHRs. In this paper, 3 works concerning about tritium in FHR are conducted: first, the tritium transport characteristics in the primary loop of FHRs are introduced, including tritium production and speciation, the absorption and desorption by graphite, dissolution and diffusion in molten salt, and permeation through structural materials. Second, the physical and mathematical models are established for tritium transport characteristic analysis in a transportable FHR (TFHR). The tritium transport characteristic analysis code (TAPAS) for TFHR is developed and benchmarked. The results prove the fidelity and accuracy of TAPAS. Finally, the tritium transport characteristics in the TFHR are analyzed systematically by TAPAS. Three conclusions are obtained: (1) tritium in the primary coolant loop is mainly in the form of T₂; (2) when TFHR operates at steady state, the permeation rate of T₂ can be regarded as a constant (9.03 × 10⁹ Bq ? EFPD^?1 ); and (3) ⁷Li enrichment and redox potential of molten salt have great influence on the tritium distribution. This work might provide contribution to the tritium control in FHRs.     

南宁吴圩国际机场新航站楼超大超厚分叉铸钢件安装技术

针对设计较为罕见的超大超厚分叉铸钢件,通过吊装软件模拟三维吊装,确保安装的安全性和可靠性,采取可靠的测量定位方法,严格按照对称焊接顺序保证铸钢件定位后的准确性和质量的保证性,解决了此超大超厚分叉铸钢件的施工难题。     

Development of TSACO and application to Chinese HCCB TBM cooling system

In this study, a thermal-hydraulic and safety analysis code (TSACO) for helium cooling system has been developed using Fortran 90 language, and the simulation has been performed for the cooling system of the Chinese helium cooled ceramic breeder test blanket module (CH HCCB TBM). The semi-implicit finite difference technique was adopted for the solution of the dynamic behavior of helium cooling system. Furthermore, a detailed illustration of the numerical solution for heat structures and critical model was presented. The code was verified by the comparison of RELAP5 code with the same initial condition, boundary condition, heat transfer and flow friction models. The TBM inlet/outlet temperatures and pressure drop were obtained and the results simulated by TSACO were shown in good agreement with those by RELAP5. Thereafter, the design basis accident in-vessel loss of coolant accident (LOCA), was investigated for the CH HCCB TBM cooling system. The critical flow model was also verified by comparing with RELAP5 code. The results indicated that the TBM can be cooled down effectively. The vacuum vessel (VV) pressure and the mass of helium spilled into the VV maintained below the design limits with a large margin.     

对城市建筑群火灾自动报警系统室外联网的探讨

阐述了城市建筑群火灾自动报警系统室外联网几种形式,及具体施工内容和注意事项.     

Effect of excess Bi content on the electrical properties of Bi0.95La0.05FeO3 thick films

BiFeO₃ (BFO)-based ferroelectric films thicker than 1 µm are promising in dielectric, piezoelectric, and pyroelectric applications. However, using the common sol–gel technology to prepare BFO-based thick films is difficult because of crack formation and poor crystallization. In this study, we demonstrate that it is possible to prepare well-crystallized Bi_0.95La_0.05FeO₃ (BLFO) thick films with a thickness of 1.4 µm by modifying excess Bi content. The effect of excess Bi content on the electrical properties of the BLFO thick film was investigated. Most excess Bi particles were found to be concentrated in the grain boundaries of thick films instead of volatilizing. Adding appropriate excess Bi when preparing BLFO thick films was also found to promote crystal growth and improve electrical properties.     

Design and fabrication of microstrip antennas integrated in three dimensional orthogonal woven composites

During the last 10 years, there has been considerable interest in the development of conformal load-bearing antenna structure (CLAS) for communication and aerospace applications. CLAS combines the antenna into a composite structure such that it can carry the designed load while functioning as an antenna. In this paper, a 3D integrated microstrip antenna (3DIMA) was designed and fabricated. The input return loss and radiation pattern of the antennas were simulated using a computer aided design tool (HFSS) and also measured experimentally. The swept input return loss curve in the range of 1–2 GHz of the 3DIMA showed a return loss of ?13.15 dB at the resonant frequency of 1.872 GHz with a voltage standing wave ratio (VSWR) of 1.56; the radiation pattern has a maximum at 180° and agrees well with the simulation results, indicating that 3DIMA can be an effective approach for a CLAS.     

Identifying differentially expressed pathways via a mixed integer linear programming model

The identification of genes and pathways involved in biological processes is a central problem in systems biology. Recent microarray technologies and other high-throughput experiments provide information which sheds light on this problem. In this article, the authors propose a new computational method to detect active pathways, or identify differentially expressed pathways via integration of gene expression and interactomic data in a sophisticated and efficient manner. Specifically, by using signal-to-noise ratio to measure the differentially expressed level of networks, this problem is formulated as a mixed integer linear programming problem (MILP). The results on yeast and human data demonstrate that the proposed method is more accurate and robust than existing approaches.