SNCR选择性非催化还原法脱硝技术在重油催化裂化装置的运用

中国石油广西石化分公司采用美国GE公司的SNCR选择性非催化还原法脱硝技术,对3.5 Mt/a催化裂化装置的CO焚烧炉进行改造。结果表明： 使用SNCR工艺后,催化裂化装置出口烟气中NOx的质量浓度由改造前的200～400 mg/m3（标准状态）,降低至70～130 mg/m3（标准状态）,排放值满足《石油炼制工业污染物排放标准》中大气污染物NOx排放值不大于200 mg/m3（标准状态）的要求,实现了达标排放,并对催化裂化装置CO焚烧炉炉膛温度影响很小,对炉膛压力及对烟气脱硫装置外排污水的pH值和氨氮含量无影响。SNCR工艺操作简单,改造量小,物耗、能耗低,在氨逃逸量小于设计值8 mg/m3（标准状态）的情况下脱硝效率高达72%。     

光探测器芯片小信号等效电路模型的建立

提出了一种光探测器芯片小信号等效电路模型及其建立方法.首先根据光探测器的物理结构确定其等效电路模型,模型考虑了影响光探测器高频性能的主要因素.然后精确测量了光探测器芯片的S参数,通过遗传算法对测量的S参数进行拟合,最终计算出模型的各个参量.在130MHz～20GHz范围内的实验结果表明,模型仿真结果与测量结果相吻合,证明了建模方法的可靠性.该模型有效地模拟了光探测器芯片的高频特性,利用该模型可以对光探测器及相应光电集成器件进行电路级仿真和优化.     

干法刻蚀对InAsP/InGaAsP应变多量子阱发光特性的影响

采用气态源分子束外延(GSMBE)生长了具有不同阱宽的InAsP/InGaAsP应变多量子阱,并对干法刻蚀前、干法刻蚀及湿法腐蚀不同厚度覆盖层后的多量子阱光致发光(PL)谱进行了表征.测量发现干法刻蚀量子阱覆盖层一定厚度后量子阱光致发光强度得到了明显的增强.这与干法刻蚀后量子阱覆盖层表面粗糙度变化及量子阱内部微结构变化有关.     

Highly Efficient Orange and Green Solid‐State Light‐Emitting Electrochemical Cells Based on Cationic IrIII Complexes with Enhanced Steric Hindrance

Highly efficient orange and green emission from single‐layered solid‐state light‐emitting electrochemical cells based on cationic transition‐metal complexes [Ir(ppy)₂sb]PF₆ and [Ir(dFppy)₂sb]PF₆ (where ppy is 2‐phenylpyridine, dFppy is 2‐(2,4‐difluorophenyl)pyridine, and sb is 4,5‐diaza‐9,9′‐spirobifluorene) is reported. Photoluminescence measurements show highly retained quantum yields for [Ir(ppy)₂sb]PF₆ and [Ir(dFppy)₂ sb]PF₆ in neat films (compared with quantum yields of these complexes dispersed in m‐bis(N‐carbazolyl)benzene films). The spiroconfigured sb ligands effectively enhance the steric hindrance of the complexes and reduce the self‐quenching effect. The devices that use single‐layered neat films of [Ir(ppy)₂sb]PF₆ and [Ir(dFppy)₂sb]PF₆ achieve high peak external quantum efficiencies and power efficiencies of 7.1 % and 22.6 lm W^–1) at 2.5 V, and 7.1 % and 26.2 lm W^–1 at 2.8 V, respectively. These efficiencies are among the highest reported for solid‐state light‐emitting electrochemical cells, and indicate that cationic transition‐metal complexes containing ligands with good steric hindrance are excellent candidates for highly efficient solid‐state electrochemical cells.     

A Thermoplastic Gel Electrolyte for Stable Quasi‐Solid‐State Dye‐Sensitized Solar Cells

Dye‐sensitized solar cells (DSSCs) are receiving considerable attention as low‐cost alternatives to conventional solar cells. In DSSCs based on liquid electrolytes, a photoelectric efficiency of 11 % has been achieved, but potential problems in sealing the cells and the low long‐term stability of these systems have impeded their practical use. Here, we present a thermoplastic gel electrolyte (TPGE) as an alternative to the liquid electrolytes used in DSSCs. The TPGE exhibits a thermoplastic character, high conductivity, long‐term stability, and can be prepared by a simple and convenient protocol. The viscosity, conductivity, and phase state of the TPGE can be controlled by tuning the composition. Using 40 wt % poly(ethylene glycol) (PEG) as the polymeric host, 60 wt % propylene carbonate (PC) as the solvent, and 0.65 M KI and 0.065 M I₂ as the ionic conductors, a TPGE with a conductivity of 2.61 mS cm^–2 is prepared. Based on this TPGE, a DSSC is fabricated with an overall light‐to‐electrical‐energy conversion efficiency of 7.22 % under 100 mW cm^–2 irradiation. The present findings should accelerate the widespread use of DSSCs.     

A location‐aware peer‐to‐peer overlay network

This work describes a novel location‐aware, self‐organizing, fault‐tolerant peer‐to‐peer (P2P) overlay network, referred to as Laptop. Network locality‐aware considerations are a very important metric for designing a P2P overlay network. Several network proximity schemes have been proposed to enhance the routing efficiency of existing DHT‐based overlay networks. However, these schemes have some drawbacks such as high overlay network and routing table maintenance overhead, or not being completely self‐organizing. As a result, they may result in poor scalability as the number of nodes in the system grows. Laptop constructs a location‐aware overlay network without pre‐determined landmarks and adopts a routing cache scheme to avoid maintaining the routing table periodically. In addition, Laptop significantly reduces the overlay maintenance overhead by making each node maintain only the connectivity between parent and itself. Mathematical analysis and simulations are conducted to evaluate the efficiency, scalability, and robustness of Laptop. Our mathematical analysis shows that the routing path length is bounded by log_d N, and the joining and leaving overhead is bounded by d log_d N, where N is the number of nodes in the system, and d is the maximum degree of each node on the overlay tree. Our simulation results show that the average latency stretch is 1.6 and the average routing path length is only about three in 10 000 Laptop nodes, and the maximum degree of a node is bounded by 32. Copyright © 2006 John Wiley & Sons, Ltd.     

Dopamine: Just the Right Medicine for Membranes

Mussel‐inspired chemistry has attracted widespread interest in membrane science and technology. Demonstrating the rapid growth of this field over the past several years, substantial progress has been achieved in both mussel‐inspired chemistry and membrane surface engineering based on mussel‐inspired coatings. At this stage, it is valuable to summarize the most recent and distinctive developments, as well as to frame the challenges and opportunities remaining in this field. In this review, recent advances in rapid and controllable deposition of mussel‐inspired coatings, dopamine‐assisted codeposition technology, and photoinitiated grafting directly on mussel‐inspired coatings are presented. Some of these technologies have not yet been employed directly in membrane science. Beyond discussing advances in conventional membrane processes, emerging applications of mussel‐inspired coatings in membranes are discussed, including as a skin layer in nanofiltration, interlayer in metal‐organic framework based membranes, hydrophilic layer in Janus membranes, and protective layer in catalytic membranes. Finally, some critical unsolved challenges are raised in this field and some potential pathways are proposed to address them.     

Peripheral Nerve‐Derived Matrix Hydrogel Promotes Remyelination and Inhibits Synapse Formation

Regeneration of injured nerve tissues requires intricate interplay of complex processes like axon elongation, remyelination, and synaptic formation in a tissue‐specific manner. A decellularized nerve matrix‐gel (DNM‐G) and a decellularized spinal cord matrix‐gel (DSCM‐G) are prepared from porcine sciatic nerves and spinal cord tissue, respectively, to recapitulate the microenvironment cues unique to the native tissue functions. Using an in vitro dorsal root ganglion–Schwann cells coculture model and proteomics analysis, it is confirmed that DNM‐G promotes far stronger remyelination activity and reduces synapse formation of the regenerating axons in contrast to DSCM‐G, Matrigel, and collagen I, consistent with its tissue‐specific function. Bioinformatics analysis indicates that the lack of neurotrophic factors and presence of some axon inhibitory molecules may contribute to moderate axonal elongation activity, while laminin β2, Laminin γ1, collagens, and fibronectin in DNM‐G promote remyelination. These results confirm that DNM‐G is a promising matrix material for peripheral nerve repair. This study provides more insights into tissue‐specific extracellular matrix components correlating to biological functions supporting functional regeneration.     

pH‐Responsive,Light‐Triggered on‐Demand Antibiotic Release from Functional Metal–Organic Framework for Bacterial Infection Combination Therapy

To satisfy the ever‐growing demand in bacterial infection therapy and other fields of science, great effort is being devoted to the development of methods to precisely control drug release and achieve targeted use of an active substance at the right time and place. Here, a new strategy for bacterial infection combination therapy based on the light‐responsive zeolitic imidazolate framework (ZIF) is reported. A pH‐jump reagent is modified into the porous structure of ZIF nanoparticles as a gatekeeper, allowing the UV‐light (365 nm) responsive in situ production of acid, which subsequently induces pH‐dependent degradation of ZIF and promotes the release of the antibiotic loaded in the mesopores. The combination of the UV‐light, the pH‐triggered precise antibiotic release, and the zinc ions enables the light‐activated nanocomposite to significantly inhibit bacteria‐induced wound infection and accelerate wound healing, indicating a switchable and synergistic antibacterial effect. The light irradiated accumulation of acid ensures the controlled release of antibiotic and controlled degradation of ZIF, suggesting the therapeutic potential of the metal–organic frameworks‐based smart platform for controlling bacterial infection.     

Graphene Oxide‐Template Controlled Cuboid‐Shaped High‐Capacity VS4 Nanoparticles as Anode for Sodium‐Ion Batteries

Room‐temperature sodium‐ion batteries have attracted great attentions for large‐scale energy storage applications in renewable energy. However, exploring suitable anode materials with high reversible capacity and cyclic stability is still a challenge. The VS₄, with parallel quasi‐1D chains structure of V⁴⁺(S₂^2?)₂, which provides large interchain distance of 5.83 Å and high capacity, has showed great potential for sodium storage. Here, the uniform cuboid‐shaped VS₄ nanoparticles are prepared as anode for sodium‐ion batteries by the controllable of graphene oxide (GO)‐template contents. It exhibits superb electrochemical performances of high‐specific charge capacity (≈580 mAh·g^?1 at 0.1 A·g^?1), long‐cycle‐life (≈98% retain at 0.5 A·g?¹ after 300 cycles), and high rates (up to 20 A·g^?1). In addition, electrolytes are optimized to understand the sodium storage mechanism. It is thus demonstrated that the findings have great potentials for the applications in high‐performance sodium‐ion batteries.