Evaluation of the economic and environmental impact of combining dry reforming with steam reforming of methane

Lately, there has been considerable interest in the development of more efficient processes to generate syngas, an intermediate in the production of fuels and chemicals, including methanol, dimethyl ether, ethylene, propylene and Fischer–Tropsch fuels. Steam methane reforming (SMR) is the most widely applied method of producing syngas from natural gas. Dry reforming of methane (DRM) is a process that uses waste carbon dioxide to produce syngas from natural gas. Dry reforming alone has not yet been implemented commercially; however, a combination of steam methane reforming and dry reforming of methane (SMR + DRM) has been used in industry for several years.     

Fe掺杂对Ba0.5Sr0.5TiO3薄膜微观结构与电学性质的影响研究

笔者利用射频磁控溅镀法在Pt/SiO2/Si(100)基板上制备出Fe掺杂量分别为0、0.5%、1.0%、2.0%、3.0%及5.0%的Ba0.5Sr0.5TiO3薄膜,并讨论了Fe掺杂含量对其微观结构结与电学性质的影响。由XRD分析可知,Fe掺杂对Ba0.5Sr0.5TiO3薄膜的晶体结构并无较大的影响;从SEM结果则可得出,微量Fe掺杂时薄膜较为致密,且晶粒大小较一致。电性结果表明,掺Fe薄膜的相对介电常数和电容均呈现下降趋势,且Fe掺杂含量分别为0.5%、1.0%及2.0%时薄膜具有较小的漏电流密度。     

基于覆盖粗糙集的地震属性约简及其应用

在油、气预测中,并非用到的地震属性越多,预测效果就越好。由于计算误差等影响,冗余地震属性反而会使预测的准确率降低。目前地震属性约简较多采用粗糙集的思想优化地震属性。然而,等价关系在有些情况下难以实现,而且连续地震属性经离散化处理后会造成原始数据失真,因此本文提出基于覆盖粗糙集的地震属性约简方法,不仅有效解决了地震属性等价关系和数据失真的问题,还克服了粗糙集理论在地震属性约简中应用的局限性,使粗糙集理论更具一般化。仿真试验和实际应用表明,通过样本地震属性约简,可以提高油、气预测精度。     

光学图像信息处理技术仿真研究

研究发现相干光图像信息处理技术和白光图像信息处理技术的共同点是信息处理技术的核心都为频域综合,这一点有利于仿真实验。本文通过对光学图像信息处理技术的仿真探索,成功地开展了相关实验,在节约实验成本的同时,弥补了课堂理论教学的不足。     

多品种盐生产线方案设计及自动配料控制

根据多品种盐生产的实际情况及对配料控制和生产工艺要求,文章介绍了一种多品种盐生产配料的自动控制系统,提出了基于PLC系统与工业总线计算机的集散型控制系统运用反馈控制。讨论了配料控制方式,介绍了选用设备和称重配料控制算法,提供了一种实用的多品种盐生产配料自动控制系统解决方案。该系统工作稳定可靠、智能化程度高、配料精度高。     

Metal/PET Composite Knitted Fabrics and Composites: Structural Design and Electromagnetic Shielding Effectiveness

Following rapid technological advances, electronic products are being used more frequently than ever, resulting in a massive amount of interference from electromagnetic waves. In this research, stainless-steel (SS) wires, copper wires, and polyester (PET) filaments were made into SS/PET, copper/PET, and SS/copper/PET composite ply yarns. These ply yarns were then knitted into electromagnetic shielding fabrics with various knitting-needle densities. In the frequency range of 1.1 GHz to 1.4 GHz, the electromagnetic shielding effectiveness (EMSE) of the SS/PET fabric was 3.8 dB greater than that of the copper/PET composite knitted fabric, demonstrating better permeability. However, in the frequency range of 0.36 GHz to 1.1 GHz, the EMSE of the copper/PET fabric was 10 dB greater than that of the SS/PET fabric, demonstrating better conductivity. The SS/copper/PET fabrics exhibited an EMSE 10 dB greater than that of the SS/PET or copper/PET fabrics.     

Comparing Through-Silicon-Via (TSV) Void/Pinhole Defect Self-Test Methods

Three methods have been proposed to test Through-Silicon-Vias (TSV) electrically prior to 3D integration. These test methods are (1) sense amplification; (2) leakage current monitor; and (3) capacitance bridge methods. These tests are aimed at detecting one or both of two failure types, pin-holes and voids. The test circuits measure capacitance and leakage current of the TSVs, and generate a 1 bit pass/fail signal. The outputs are streamed out through a scan chain. The test time is 10 μs for the leakage test and the sense amplification methods, and is 15 μs for the capacitive bridge method. All these methods can be implemented for test-before-stacking, which will increase assembled yield. Resolution, power and area of these TSV test circuits were compared. The performance of each circuit was studied at PVT corners. The IMEC TSV technology was assumed, and the designs were simulated using the 32 nm predicted device model. Without any failure, the TSV capacitance’s mean value is 37 fF, and its leakage resistance is higher than 850 MΩ. With respect to 37 fF standard capacitance, resolution for the sense amplification method is 3.3 fF (8.9%); it is 0.16 fF (0.4%) for the capacitance bridge method. Although the capacitance bridge method has relatively better resolution, it takes 4x area and 10x power than the other two, and is also more sensitive to PVT variation. Resolution of the leakage current monitor method is 10 MΩ (1.1%) with respect to its threshold 850 MΩ, and use 42.5aJ power in normal case. Sense amplification circuit can be modified to detect equivalent leakage resistance under 2KΩ.     

激光技术新进展及其在光伏产业中的应用

自从1960年世界上第一台红宝石激光器问世以来,激光技术有了很大的发展,已经从实验室走向应用。激光技术的一些新进展包括:光学设备和材料,从中红外到紫外波段新材料;激光应用中的新型激光源、光纤传感、激光冷却、激光加工;光伏技术:薄膜电池、有机光伏电池、高效光伏电池。重点介绍了以透明陶瓷为代表的新型激光材料,以光纤激光为代表的新型激光器结构,以掺铥光纤激光器为代表的中红外激光器;并介绍了激光技术在光伏太阳能产业中的应用。     

On energy efficiency of geographic opportunistic routing in lossy multihop wireless networks

Geographic opportunistic routing (GOR) is an emerging technique that can improve energy efficiency in lossy multihop wireless networks. GOR makes local routing decision by using nodes?? location information, and exploits the broadcast nature and spatial diversity of the wireless medium to improve the packet forwarding reliability. In this paper, our goal is to fully understand the principles and tradeoffs in GOR, thus provide insightful analysis and guidance to the design of more efficient routing protocols in multihop wireless networks. We propose a local metric, one-hop energy efficiency (OEE), to balance the packet advancement, reliability and energy consumption in GOR. We identify and prove important properties about GOR on selecting and prioritizing the forwarding candidates in order to maximize the expected packet advancement. Leveraging the proved properties, we then propose two localized candidate selection algorithms with O(N ³) running time to determine the forwarding candidate set that maximizes OEE, where N is the number of available next-hop neighbors. Through extensive simulations, we show that GOR applying OEE achieves better energy efficiency than the existing geographic routing and blind opportunistic routing schemes under different node densities and packet sizes.     

Flexible Hybrid Paper Made of Monolayer Co3O4 Microsphere Arrays on rGO/CNTs and Their Application in Electrochemical Capacitors

A facile one‐step hydrothermal method is developed for large‐scale production of well‐designed flexible and free‐standing Co₃O₄/reduced graphene oxide (rGO)/carbon nanotubes (CNTs) hybrid paper as an electrode for electrochemical capacitors. Densely packed unique Co₃O₄ monolayer microsphere arrays uniformly cover the surface of the rGO/CNTs film. The alkaline hydrothermal treatment leads to not only the deposition of Co₃O₄ microspheres array, but also the reduction of the GO sheets at the same time. The unique hybrid paper is evaluated as an electrode for electrochemical capacitors without any ancillary materials. It is found that the obtained hybrid flexible paper, composed of Co₃O₄ microsphere array anchored to the underling conductive rGO/CNTs substrate with robust adhesion, is able to deliver high specific capacitance with excellent electrochemical stability even at high current densities, suggesting its promising application as an efficient electrode material for electrochemical capacitors.