复杂地质条件气藏储气库库容参数的预测方法

国内复杂地质条件气藏型地下储气库经过10余周期注采后工作气量仅为建库方案设计工作气量的一半,运行效率偏低。为此,利用气藏地质、动态及建库机理,建立了地下储气库注采运行剖面模型,根据气藏开发、气藏建库及稳定注采运行过程中纵向上流体的分布特征及其变化趋势,将地下储气库剖面分成4个区带(建库前纯气带、气驱水纯气带、气水过渡带及水淹带);按区带确定了影响建库有效孔隙体积的主控因素(储层物性及非均质性、水侵和应力敏感)及其量化评价方法,进一步考虑束缚水和岩石形变的影响,并引入注气驱动相,根据注采物质平衡原理建立了气藏型地下储气库库容参数预测数学模型。该模型涵盖了地质、动态及建库机理,从微观和宏观角度综合评价了影响建库空间的主控因素,大大提高了预测结果的准确度和精度,使建库技术指标设计更趋合理,目前已广泛应用于中国石油天然气集团公司气藏型地下储气库群的建设当中。     

达芬奇异构多核处理器核间通信技术研究

针对目前通用的达芬奇异构多核处理器,研究了其ARM核、DSP核以及视频协处理器之间的通信与协作机制.在分析多核处理器核间通信原理的基础上,研究了TMS320DM816x系列达芬奇异构多核处理器的核间通信技术,详细阐述片上核间互联结构与核间通信软件的实现.最后基于SysLink底层通信模块设计了多路高清音视频应用系统,对核间通信进行验证.系统可充分发挥各处理核的性能,实现了各核间的高效协作.     

Developing crash modification functions to assess safety effects of adding bike lanes for urban arterials with different roadway and socio-economic characteristics

Although many researchers have estimated crash modification factors (CMFs) for specific treatments (or countermeasures), there is a lack of studies that explored the heterogeneous effects of roadway characteristics on crash frequency among treated sites. Generally, the CMF estimated by before–after studies represents overall safety effects of the treatment in a fixed value. However, as each treated site has different roadway characteristics, there is a need to assess the variation of CMFs among the treated sites with different roadway characteristics through crash modification functions (CMFunctions). The main objective of this research is to determine relationships between the safety effects of adding a bike lane and the roadway characteristics through (1) evaluation of CMFs for adding a bike lane using observational before–after with empirical Bayes (EB) and cross-sectional methods, and (2) development of simple and full CMFunctions which are describe the CMF in a function of roadway characteristics of the sites. Data was collected for urban arterials in Florida, and the Florida-specific full SPFs were developed. Moreover, socio-economic parameters were collected and included in CMFunctions and SPFs (1) to capture the effects of the variables that represent volume of bicyclists and (2) to identify general relationship between the CMFs and these characteristics. In order to achieve better performance of CMFunctions, data mining techniques were used.     

Photoelectrocatalytic hydrogen production of heterogeneous photoelectrodes with different system configurations of CdSe nanoparticles,Au nanocrystals and TiO2 nanotube arrays

The different configurations of CdSe nanoparticles, Au nanocrystals and TiO₂ nanotube arrays play an important role in the photoelectrochemical behavior and photoelectrocatalytic hydrogen production of this heterogeneous photoelectrode system. It is discovered that the photoelectrocatalytic hydrogen production of the TiO₂–CdSe–Au photoelectrode (1.724 mmol g⁻¹ h⁻¹) is about 4 times that of the TiO₂–Au–CdSe photoelectrode (0.430 mmol g⁻¹ h⁻¹) under visible light irradiation. From the comprehensive investigation of their photoelectrochemical behaviors, it is illustrated that the interfacial electrical field has distinct effects on the separation and transportation of photogenerated carriers in these heterostructure photoelectrodes. The directions of the interfacial electrical fields formed at TiO₂–Au and Au–CdSe interfaces are opposite in the TiO₂–Au–CdSe photoelectrode, which hinders the separation of photogenerated electron-hole pairs and subsequent transportation of photogenerated carriers. On the contrary, the directions of the interfacial electrical fields formed at TiO₂–CdSe and CdSe–Au interfaces are identical in the TiO₂–CdSe–Au photoelectrode, which promotes the separation of photogenerated excitons and subsequently enhances their transportation for enlarged photocurrent density. The results of photoelectrocatalytic hydrogen production also confirm our assumption.     

Resource-awareness on heterogeneous MPSoCs for image processing

Multiprocessor system-on-chip (MPSoC) designs offer a lot of computational power assembled in a compact design. The computing power of MPSoCs can be further augmented by adding massively parallel processor arrays (MPPA) and specialized hardware with instruction-set extensions. On-chip MPPAs can be used to accelerate low-level image-processing algorithms with massive inherent parallelism. However, the presence of multiple processing elements (PEs) with different characteristics raises issues related to programming and application mapping, among others. The conventional approach used for programming heterogeneous MPSoCs results in a static mapping of various parts of the application to different PE types, based on the nature of the algorithm and the structure of the PEs. Yet, such a mapping scheme independent of the instantaneous load on the PEs may lead to under-utilization of some type of PEs while overloading others.In this work, we investigate the benefits of using a heterogeneous MPSoC for accelerating various stages within a real-world image-processing algorithm for object-recognition. A case study demonstrates that a resource-aware programming model called Invasive Computing helps to improve the throughput and worst observed latency of the application program, by dynamically mapping applications to different types of PEs available on a heterogeneous MPSoC.     

Catalytic hydrodeoxygenation and hydrocracking of Alcell® lignin in alcohol/formic acid mixtures using a Ru/C catalyst

The catalytic conversion of Alcell^® lignin in iso-propanol/formic acid mixtures (1:1 mass ratio) was explored in a batch set-up using Ru/C as the catalyst (673 K, 4 h, 28% mass lignin intake on solvent). Lignin oils were obtained in good yields (71% mass yields on lignin input) and shown to consist of a mixture of mainly aromatics (10.5% mass yields on lignin input), alkylphenolics (6% mass yields on lignin input), catechols (8.7% mass yields on lignin input), guaiacols (1.3% mass yields on lignin input), and alkanes (5.2% mass yields on lignin input), the remainder being soluble higher molecular weight compounds (GCxGC-FID and GPC). The results for the catalytic experiments using formic acid were compared with those of a non-catalysed experiment and a catalytic hydrotreatment with molecular hydrogen and Ru/C in the absence of a solvent. Distinct differences in product yields and compositions were observed, and highest lignin oil yields were obtained by catalytic solvolysis (71% mass yields on lignin input) versus 18% mass yields on lignin input for non-catalytic solvolysis and 63% mass yields on lignin input for catalytic hydrotreatment. The effect of reaction time on oil yields and product composition was established and a reaction network involving depolymerisation, and hydro(-deoxy)genation pathways is proposed to explain the product yields and composition. Besides iso-isopropanol, the use of ethanol and methanol in combination with formic acid was also explored for catalytic solvolysis. Best results were obtained in methanol (4 h, 673 K) leading to a lignin oil (68% mass yields on lignin input) containing 11% mass yields on lignin input of alkylphenolics and 19% mass yields on lignin input of aromatics.     

Hierarchical particle swarm optimizer for minimizing the non-convex potential energy of molecular structure

The stable conformation of a molecule is greatly important to uncover the secret of its properties and functions. Generally, the conformation of a molecule will be the most stable when it is of the minimum potential energy. Accordingly, the determination of the conformation can be solved in the optimization framework. It is, however, not an easy task to achieve the only conformation with the lowest energy among all the potential ones because of the high complexity of the energy landscape and the exponential computation increasing with molecular size. In this paper, we develop a hierarchical and heterogeneous particle swarm optimizer (HHPSO) to deal with the problem in the minimization of the potential energy. The proposed method is evaluated over a scalable simplified molecular potential energy function with up to 200 degrees of freedom and a realistic energy function of pseudo-ethane molecule. The experimental results are compared with other six PSO variants and four genetic algorithms. The results show HHPSO is significantly better than the compared PSOs with p-value less than 0.01277 over molecular potential energy function.     

PdCoNi nanoparticles supported on nitrogen-doped porous carbon nanosheets for room temperature dehydrogenation of formic acid

The development of cost-effective heterogeneous catalysts for the dehydrogenation of formic acid (FA) is the key challenge for the commercialization of FA as a hydrogen-storage medium. Herein, PdCoNi nanoparticles (NPs) with different element ratios supported on N-doped carbon nanosheets (N-CN) were designed, which exhibit excellent catalytic dehydrogenation performance for FA. Compared with PdCoNi NPs loaded on the carbon nanosheets (CN), the introduction of pyrrolic N to CN induces the formation of ultrafine, monodispersed and amorphous Pd_0.6Co_0.2Ni_0.2 NPs with a size of 1.60 nm, which significantly increases the number of active sites and the instant contact between FA and catalysts. The as-prepared Pd_0.6Co_0.2Ni_0.2/N-CN catalyst shows more than 99% conversion and 100% H₂ selectivity at room temperature, with a record-high initial turnover frequency (TOF_initial) of 1249.0 h⁻¹ among non-noble containing Pd-based catalysts, which demonstrates the high potential of Pd_0.6Co_0.2Ni_0.2/N-CN as a practical catalyst for the hydrogen generation from FA.     

Production of biodiesel from castor oil using iron (II) doped zinc oxide nanocatalyst

The depletion of fossil fuels has caused the price of petroleum to rise remarkably and created need for alternative energy such as biodiesel. In the present study, the biodiesel was produced from castor oil using ferromagnetic zinc oxide nanocomposite as heterogeneous catalyst for transesterification reaction. Single phase of nanocatalyst were confirmed by X-Ray Diffraction analysis. The spherical shape of the aggregated nanocatalyst was observed in Scanning Electron Microscopy. Magnetic properties were analysed using vibrating sample magnetometer. Atomic Force Microscopic analysis revealed the larger surface area and roughness of nanocatalyst. The biodiesel yield of 91% (w/w) was obtained in 50 min at 55 °C with 14 wt % catalyst loading and 12:1 methanol/oil ratio and was confirmed by Gas chromatograph with Mass Spectrometer. The result showed that the iron (II) doped ZnO nanocatalyst is a promising catalyst for the production of biodiesel via heterogeneous catalytic transesterification under milder reaction conditions.     

重塑“异质空间”唤起小镇新生——德国达豪集中营纪念地设计意匠解析

就像社会的“另类”人群一样，城市中存在着一些由于历史原因而遗留的，与原有城市的空间肌理、建筑形态大相径庭的异质空间。这类异质空间具有相当的历史意义和文化价值，但必须通过合理而富于创造性的改造设计使之重新融入到新的城市结构体系中，才能获得重生，否则将难以避免地被新的秩序所替代而最终走向消亡。本文以德国达豪集中营纪念地为例，详细分析了其设计对原有空间逻辑的延续与改造，引发了对利用异质空间营造城市纪念性空间的思考。