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71.
顺酐化SBS的钠离聚体形式与丙烯酰胺的乳液接枝共聚 总被引:2,自引:0,他引:2
研究了顺酐化SBS的钠离聚体与丙烯酸胺以过氧化苯甲酰为引发剂的乳液聚合,得到了共聚的较佳条件.并以IR及DSC表征了试样的组成和多相结构. 相似文献
72.
73.
一次多级离心泵运行故障处理及分析 总被引:1,自引:0,他引:1
简要介绍了实际生产中多级离心泵存在的问题,并分析了故障原因和处理措施。 相似文献
74.
沉淀铁催化剂上F-T合成反应的研究 总被引:2,自引:1,他引:2
制备了物相组成为 Quartz- Si O2 ,Hermatite- Fe2 O3 和 Fe2 O3 - Iron Oxide的沉淀铁催化剂 ,研究了该催化剂作用上固定床积分反应器中费托合成反应特性 .发现 2 .6MPa,80 0 h-1,H2 /CO=2 /3,2 60℃~ 2 90℃时 ,随着温度的升高 ,CO和 H2 的转化率增大 ,CO2 选择性减小 ;40 0 h-1,65 0 h-1,80 0 h-1低空速和 2 4 0 0 h-1,32 0 0 h-1,40 0 0 h-1,640 0 h-1高空速时 ,随着空速的升高 ,H2转化率、CO转化率选择性下降 ,CO2 的选择性升高 ;2 80℃ ,2 .6MPa,H2 /CO进料比 2 /3,1 /1 ,2 /1时 ,随着 H2 /CO进料比的增加 ,CO转化率 ,H2 /CO利用比和 CH4选择性都增加 ,H2 转化率和 CO2选择性减小 . 相似文献
75.
A novel sol–gel method based on V2O5·nH2O hydro-gel was developed to synthesize nanocrystalline Li3V2(PO4)3/carbon composite material. In this route, V2O5·nH2O hydro-gel, NH4H2PO4, Li2CO3 and high-surface-area carbon were used as starting materials to prepare precursor, and the Li3V2(PO4)3/carbon was obtained by sintering precursor at 750 °C for 4 h in flowing argon. The sol–gel synthesis ensures homogeneity of the precursors and improved reactivity. The sample was characterized by XRD, SEM and TEM. X-ray diffraction results show Li3V2(PO4)3 sample is monoclinic structure with the space group of P21/n. The TEM image indicates that the Li3V2(PO4)3 particles modified by conductive carbon are about 70 nm in diameter. The Li3V2(PO4)3/carbon system showed that the discharge capacities in the first and 50th cycle are about 155.3 and 143.6 mAh/g, respectively, in the range of 3.0–4.8 V. The sol–gel method is fit for the preparation of Li3V2(PO4)3/carbon composite material which may offer some favorable properties for commercial application. 相似文献
76.
本文介绍了一个微机上运行的注塑模CAD系统,此系统主要解决了四个难点,浇注系统设计,冷却系统分析,型腔,型芯的曲面造型设计,装配图和零件工作图的设计绘制,经厂家实际运用证明,该系统使用方便,结果正确,能提高设计效率,降低生产成本。 相似文献
77.
Claudia Kuster Jean‐Charles Bazin Cengiz Öztireli Teng Deng Tobias Martin Tiberiu Popa Markus Gross 《Computer Graphics Forum》2014,33(2):1-10
Multi‐view reconstruction aims at computing the geometry of a scene observed by a set of cameras. Accurate 3D reconstruction of dynamic scenes is a key component for a large variety of applications, ranging from special effects to telepresence and medical imaging. In this paper we propose a method based on Moving Least Squares surfaces which robustly and efficiently reconstructs dynamic scenes captured by a calibrated set of hybrid color+depth cameras. Our reconstruction provides spatio‐temporal consistency and seamlessly fuses color and geometric information. We illustrate our approach on a variety of real sequences and demonstrate that it favorably compares to state‐of‐the‐art methods. 相似文献
78.
Large volume of online review data can reveal consumers’ major interests on domain product, which attracts great research interests from the academic community. Most of the existing works focus on the problems of review summarization, aspect identification or opinion mining from an item’s point of view such as the quality or popularity of products. Considering the fact that users who generate those review texts draw different attentions to product aspects with respect to their own interests, in this article, we aim to learn K users’ interest groups indicated by their review writings. Such K interest groups’ identification can facilitate better understanding of major and potential consumers’ concerns which are crucial for applications like product improvement on customer-oriented design or diverse marketing strategies. Instead of using a traditional text clustering approach, we treat the groupId/clusterId as a hidden variable and use a permutation-based structural topic model called KMM. Through this model, we infer K interest groups’ distribution by discovering not only the frequency of product aspects (Topic Frequency), but also the occurrence priority of respective aspects (Topic Order). They jointly present an informative summarization on the raw review corpus. Our experiment on several real-world review datasets demonstrates a competitive solution. 相似文献
79.
Aihong Ren Yuping Wang Xingsi Xue 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2014,18(5):995-1009
In this paper, we address a class of bilevel linear programming problems with fuzzy random variable coefficients in objective functions. To deal with such problems, we apply an interval programming approach based on the $\alpha $ -level set to construct a pair of bilevel mathematical programming models called the best and worst optimal models. Through expectation optimization model, the best and worst optimal problems are transformed into the deterministic problems. By means of the Kth best algorithm, we obtain the best and worst optimal solutions as well as the corresponding range of the objective function values. In this way, more information can be provided to the decision makers under fuzzy random circumstances. Finally, experiments on two examples are carried out, and the comparisons with two existing approaches are made. The results indicate the proposed approaches can get not only the best optimal solution (ideal solution) but also the worst optimal solution, and is more reasonable than the existing approaches which can only get a single solution (ideal solution). 相似文献
80.