大孔树脂法精制甘草酸

介绍了用大孔树脂从甘草中分离精制甘草酸的方法。大孔树脂是目前广泛采用的分离天然产物的方法。用大孔树脂精制甘草酸,使甘草酸和其他杂质得到很好的分离,明显改善了甘草酸的质量。在纯度测定时,采用香草醛-硫酸比色法能准确测定甘草酸纯度。另外,实验使用草酸还原Fe3+的方法改善产品颜色,并在进样前先用活性炭脱色,这两种方法同时使用有效地改善了产品的颜色。     

Stresses of cohesionless granular flows in liquids

We construct constitutive relations for friction stress, slide stress and collision stress of cohesionless granular flows. We propose that the friction stress and slide stress could be neglected when τ_c/τ_e < 0.02, where τ_c represents the interval time experienced by a given particle between two consecutive binary collisions and τ_e the particle relaxation time. We applied these constitutive relations to a simulation of solid-liquid flow in an inclined chute and found the simulation results agree with experimental data.     

Synthesis and electrochemical performance of LiNi0.5Mn1.5O4 spinel compound

Spinel compound LiNi_0.5Mn_1.5O₄ was synthesized by a chemical wet method. Mn(NO₃)₂, Ni(NO₃)₂·6H₂O, NH₄HCO₃ and LiOH·H₂O were used as the starting materials. At first, Mn(NO₃)₂ and Ni(NO₃)₂·6H₂O reacted with NH₄HCO₃ to produce a precursor, then the precursor reacted with LiOH·H₂O to synthesize product LiNi_0.5Mn_1.5O₄. The product showed a single spinel phase under appropriate calcination conditions, and exhibited a high voltage plateau at about 4.6-4.8 V in the charge/discharge process. The LiNi_0.5Mn_1.5O₄ had a discharge specific capacity of 118 mAh/g at about 4.6 V and 126 mAh/g in total in the first cycle at a discharge current density of 2 mA/cm². After 50 cycles, the total discharge capacity was above 118 mAh/g.     

新型有机磷系阻燃剂的热稳定性

利用STA490C热分析仪对8种新型有机磷系阻燃剂的热失重过程进行测定和对比,结果表明磷杂螺环阻燃剂3,9-二羟基-2,4,8,10-四氧杂-3,9-二磷杂螺环[5,5]十一烷-3,9-二氧化物和苯基次膦酸类阻燃剂4-甲氧基羟甲基苯基次膦酸热稳定性较好。     

SBS在胶粘剂领域中的应用及开发进展

综述了国内外SBS在胶粘剂领域中的应用及开发进展以及合成胶粘剂用SBS热塑性弹性体的研究状况,并最终从原料SBS产品的物性、微观结构与胶粘剂产品的性能之间的关系出发,提出了制备新功能胶粘剂产品用苯乙烯-丁二烯嵌段共聚物的途径。     

不同预处理条件下纤维素的结构变化及其在DMAc／LiCI中的溶解

介绍了乙二胺、氢氧化钠和高温等三种不同的纤维素预处理方法。研究预处理后纤维素的结构变化，讨论预处理过程中的转化机理，并通过X射线衍射对纤维素结晶度的变化进行表征，证明乙二胺预处理后纤维素的结晶度下降最大。纤维素经过预处理后可以溶解在DMAc／LiCI中，讨论其溶解机理，通过对比三种预处理纤维素的溶解性能，表明经过乙二胺预处理之后的纤维素在DMAc／LiCI中溶解性能最好，氢氧化钠预处理的纤维素次之，高温预处理的纤维素溶解性能相对较差。     

Coupling-and-decoupling: A hierarchical model for occlusion-free object detection

Handling occlusion is a very challenging problem in object detection. This paper presents a method of learning a hierarchical model for X-to-X occlusion-free object detection (e.g., car-to-car and person-to-person occlusions in our experiments). The proposed method is motivated by an intuitive coupling-and-decoupling strategy. In the learning stage, the pair of occluding X?s (e.g., car pairs or person pairs) is represented directly and jointly by a hierarchical And–Or directed acyclic graph (AOG) which accounts for the statistically significant co-occurrence (i.e., coupling). The structure and the parameters of the AOG are learned using the latent structural SVM (LSSVM) framework. In detection, a dynamic programming (DP) algorithm is utilized to find the best parse trees for all sliding windows with detection scores being greater than the learned threshold. Then, the two single X?s are decoupled from the declared detections of X-to-X occluding pairs together with some non-maximum suppression (NMS) post-processing. In experiments, our method is tested on both a roadside-car dataset collected by ourselves (which will be released with this paper) and two public person datasets, the MPII-2Person dataset and the TUD-Crossing dataset. Our method is compared with state-of-the-art deformable part-based methods, and obtains comparable or better detection performance.     

Evaluation of two alternative carbon capture and storage technologies: A stochastic model

In this paper we evaluate two alternative CCS technologies at a coal-fired power plant from an investor's point of view. The first technology uses CO₂ for enhanced oil recovery (EOR) paired with storage in deep saline formations (DSF) and the second merely stores CO₂ in DSF. The paper updates and improves on an earlier publication by Tzimas et al. (2005). For projects of this type there are many sources of risk, three of which stand out: the price of electricity, the price of oil and the price of carbon allowances. In this paper we develop a general stochastic model that can be adapted to other projects such as enhanced gas recovery (EGR) or industrial plants that use CO₂ for either EOR or EGR with CCS. The model is calibrated with UK data and applied to help understand the conditions that generate the incentives needed for early investments in these technologies. Additionally, we analyse the risks of these investments. Investments with EOR and secondary DSF storage can only be profitable (NPV > 0) when there is a high long-term equilibrium price for oil of more than $56.38/barrel. When the investment decision can be made at any time, i.e. there is an option value, then the trigger value for optimal investment is significantly higher.     

A noisy-smoothing relevance feedback method for content-based medical image retrieval

In this paper, we address a new problem of noisy images which present in the procedure of relevance feedback for medical image retrieval. We concentrate on the noisy images, caused by the users mislabeling some irrelevant images as relevant ones, and a noisy-smoothing relevance feedback (NS-RF) method is proposed. In NS-RF, a two-step strategy is proposed to handle the noisy images. In step 1, a noisy elimination algorithm is adopted to identify and eliminate the noisy images. In step 2, to further alleviate the influence of noisy images, a fuzzy membership function is employed to estimate the relevance probabilities of retained relevant images. After noisy handling, the fuzzy support vector machine, which can take into account different relevant images with different relevance probabilities, is adopted to re-rank the images. The experimental results on the IRMA medical image collection demonstrate that the proposed method can deal with the noisy images effectively.     

组合填料-膜生物反应器处理生活污水生产性试验

在一体式膜生物反应器（MBR）中加入组合填料，对北京某国际公寓的生活污水处理进行了生产性试验。试验表明，在进水水温15～22℃，pH值6．5～7．2，曝气气水体积比9～10：1，COD198．6～563．5mg／L，NH4-N20．5～55．3mg／L，反应器中混合液悬浮固体浓度（MLSS）维持在5200～7800mg／L时，MBR对水中的COD、NH4^＋-N平均去除率分别为90．6％、68．7％，出水中检测不出SS和大肠菌群，浊度小于1NTU，水质满足CJ2511-89《生活杂用水水质标准》。在相同条件下，未加填料反应器MLSS平均值必须维持在12000mg／L以上时才能达到类似处理效果。由于反应器中加入组合填料，降低了MLSS的浓度，减少了膜污染，在膜通量不变情况下，化学清洗周期可延长35～40d。