连续熔硫工艺的研制与应用

介绍了用湿法脱硫后的硫泡沫生产熔融硫的研制过程。该工艺熔硫效率高,节能效果好,可以连续操作．并可实现自动化、管道化操作。熔硫器体积小、重量轻、操作弹性大。     

Two-echelon multi-product multi-constraint product returns inventory model with permissible delay in payments and variable lead time

Supply chain is not limited to delivering products to the end-costumers since the defective products that are returned back to the producers by the consumers. The producers should be superior knowledge to utilize the return products effectively so as to maintain our natural resources and to provide better service to customers. In this paper, a distributor and a warehouse consisting of a serviceable part and a recoverable part supply chain problem is considered in which there are several products, the distributor has limited space capacity and budget to purchase all products. In this supply chain, the defective products are returned back to the warehouse by the distributor and the warehouse recovered those defective products into perfect products having the same value as the procured products. The lead-time of receiving products from a warehouse to a distributor is a variable which is controllable by adding extra crashing cost. For each product, a fraction of the shortage is backordered and the rest are lost. A mathematical model is employed in this study for optimizing the order quantity, lead time and total number of deliveries with the objective of minimizing system total cost. We show that the model of this problem is a constrained non-linear programme and present a simple Lagrangian multiplier technique to solve it. Numerical and sensitivity analysis are given to show the applicability of the proposed model in real-world product returns inventory problems.     

Continuous space maximal coverage: Insights,advances and challenges

Siting facilities in continuous space to maximize coverage of regional demand is an important planning problem. It is challenging to solve because demand is continuously distributed in a region and facilities may be sited anywhere in the region, suggesting that an infinite number of locations must be considered both as demand for service as well as a potential facility. An ingenious approach for solving continuous space coverage problems is abstracting continuously distributed demand as discrete spatial objects (points, lines or polygons), generating a finite dominating set from continuous space as candidate facility sites, and applying a discrete location coverage model. However, abstracting continuous demand and potential facility sites often introduces errors and uncertainties in coverage of regional demand, rendering findings (service and optimal facility locations) less than definitive. In this paper we examine the continuous space maximal coverage problem. Studies focused on locating antennas in Paradise Valley, Arizona and emergency warning sirens in Dublin, Ohio, are used to highlight issues and challenges in continuous space modeling. Potential paths forward are suggested based on empirical insights.     

Optimization of H2 photo-fermentation from benzoate by Rhodopseudomonas palustris using a desirability function approach

The operational conditions of H₂ production from benzoate by Rhodopseudomonas palustris was optimized in batch experiments by using the response surface methodology (RSM) and a desirability function approach. The estimated best H₂ production performance, i.e., maximum substrate-to-hydrogen conversion efficiency of 0.61 and light conversion efficiency of 3.20%, was achieved at: benzoate concentration 9.97 mM, NH₄Cl concentration 0.21 g/L and pH 6.76. These parameters were employed for running a continuous H₂ production bioreactor, for which the optimal hydraulic retention time was found to be 6 d. Under a light–dark cycle, R. palustris survived and maintained their H₂ production activity in the continuous operating system. The results demonstrate that it is possible to operate an outdoor photo-bioreacror for continuous H₂ production by utilizing aromatic compound as substrate. This works offer implications for guiding the design and operation of more energy–productive processes for treatment of aromatic compound-containing wastewater treatment.     

Development of efficient production routes based on strip casting for advanced high strength steels for crash-relevant parts

Twin roll strip casting can be an effective alternative to produce high manganese TWIP steel, which provides extraordinary mechanical properties. In the work presented, 1.5–3 mm thin hot strips with up to 30 wt% manganese were produced directly from the melt and further processed to cold strip. An adapted thermo-mechanical treatment, consisting of cold rolling with or without subsequent annealing, enables to adjust different material states, such as recrystallised or strengthened state, and thus to tailor the mechanical properties. As an example for the superior crash behaviour of high manganese TWIP steels, dynamic crash tests were carried out using cold rolled Fe–29Mn–0.3C steel in different material states.     

Development of an 8090/3003 bimetal slab using a modified direct-chill casting process

A modified direct-chill (DC) casting method was used to prepare an 8090/3003 bimetal slab of aluminum alloys with consistent mechanical properties. The interface of the as-cast bimetal material was free of detrimental intermetallic compounds, which indicated excellent metallurgical bonding. A diffusion layer with an average thickness of approximately 80 μm was obtained due to the interdiffusion of Li, Mg, Cu and Mn at the bimetal interface. The average ultimate tensile strength of the as-cast bimetal slab was 101 MPa, and all fractures occurred on the side of the softer 3003 alloy. T6 treatment was performed on the bimetal slab to investigate the response of the slab to heat treatment. The Vickers hardness of the 8090 side increased by 30% after T6 treatment, reaching 153 HV. The Vickers hardness of the interface layer also increased from 70 HV to 89 HV. The solution strengthening was considered to make the primary contributions on the hardness improvement of the bimetal slab at the interface after T6 treatment.     

A preliminary study on optimizing the heat treatment of high strength Al–Cu–Mg–Zn alloys

The design of critical aerospace alloys is primarily built on optimizing strength and ductility, both of which can be enhanced by controlling the alloying element additions as well as heat treatment conditions. The 7075 alloy is one such aerospace alloy. The main objective of this study was to optimize the 7075 strength. Several experimental alloys were prepared and tensile test bars were cast using an ASTM B-108 type permanent metallic mold. The as-cast samples were then solution heat-treated at 470 °C for times up to 48 h. The solution heat-treated bars were also aged in order to improve the alloy strength through precipitation hardening. Line scans for Mg, Cu and Zn were obtained from the various heat-treated alloy samples using an electron probe microanalyzer equipped with Energy Dispersive X-ray (EDX) and Wavelength Dispersive Spectroscopic (WDS) facilities. Peaks corresponding to the Mg, Cu and Zn concentrations in the as-cast samples disappeared after solution treatment, reflecting optimized homogeneity structures. The newly developed versions of the 7075 alloy displayed an ultimate tensile strength (UTS) of ∼1 GPa.     

HMM based recognition of Chinese tones in continuous speech

This paper describes a method for recognizing Chinese tones in continuous speech. The first and second order differentials of the fundamental frequency logarithmically converted are used as feature parameters. A left-to-right hidden Markov modeling with five states, each of which is modeled by a single Gaussian distribution, expresses each of Chinese tones. Non-voiced portions are coded by random values normally distributed to uniformly deal with all the time frames in an utterance. Speaker dependent tone recognition was conducted for ten speakers. The average rate of 81.8% was obtained for these speakers.     

高功率二极管泵浦固体激光器的技术问题和应用前景分析

本文基于近年来的工作，对高功率二极管泵浦固体激光器的一些关键技术问题进行了分析，提出了向更高功率水平发展可行的技术方案，并讨论了应解决的关键问题，最后展望了高功率二极管泵浦固体激光器的应用前景。     

国产连续重整成套技术在装置扩能改造中的应用

 介绍了洛阳石化700kt/a重整装置使用国产连续重整成套技术进行改造的情况,对装置的开工过程及标定结果进行了叙述和说明,对装置运行过程中出现的压缩机喘振、催化剂循环提升不畅、催化剂再生设备腐蚀等问题进行了分析,采取相应的措施进行了整改优化,对工艺流程进行了改进,使装置生产达到了满负荷稳定运行状态。结果表明,洛阳石化重整采用国产技术进行改造取得了成功,重整生成油的质量和处理量有了明显的提高;同时,该技术填补了国产连续重整工艺的空白,为国内其它同类装置进行扩能改造提供了经验,为国产"超低压连续重整成套技术"实现工业化应用奠定了基础。