Cooperative effect of crystallization temperature and NaF addition in the formation process and hydrothermal stability of MCM-48 mesoporous molecular sieve

The hydrothermal stability of MCM-48 was conveniently and effectively improved by increasing the crystallization temperature and directly adding NaF to the synthesis gel. The crystallization temperature varied from 373 K to 403 K. The influences of NaF addition, crystallization temperature and crystallization time on the formation process and hydrothermal stability of MCM-48 were systematically studied here to solve the problem of poor reproducibility. Results from XRD patterns indicated that the crystallization temperature and crystallization time were very critical factors for the improvement of the hydrothermal stability besides NaF addition. The formation process of MCM-48 was significantly accelerated and the pore structure ordering was also greatly improved by increasing the crystallization temperature and F⁻/Si ratio. A high hydrothermally stable MCM-48 mesoporous molecular sieve was obtained after being crystallized at 393 K for 36 h in the presence of NaF, which endured the hydrothermal treatment in boiling water at least for 4 days. However, only an amorphous product was obtained when the crystallization temperature was further increased to 403 K. Results from Si MAS NMR, N₂ adsorption isotherms, TEM, Raman spectra and XRD patterns manifested that the improved stability of MCM-48 was attributed to the high silicates condensation degree and the excellent pore structure ordering. The possible reason for the successful formation of hydrothermally stable MCM-48 sample by controlling the crystallization temperature, time and F⁻/Si ratio was explained here.     

设计企业项目管理信息系统的实现

结合国家“十五”重点科技攻关计划“城市规划、建设、管理与服务数字化工程”项目,天津水泥工业设计研究院承担了其中的“勘察设计企业信息化应用软件示范应用”专题,并获批立项,签署了专题任务书。两年来,院项目实施小组和软件公司进行了长期、紧密的合作,遵照标准化、系统化和集成化的原则,共同搭建了“工程协同设计管理平台”。在软件功能上,实现了设计企业管理信息系统的主要功能;在软件技术上,采用了目前最流行的软件技术,结合现代项目管理方法,为设计企业提供了组态灵活,方便实用,具有良好扩展性及开放性的软件产品。目前,该系统已经在部分工程项目上全面运行,取得了预期的效果。     

Irganox(R) HP-136的抗氧化机理及对聚丙烯加工稳定性的影响

介绍了Irganox(R) HP-136在PP加工中的作用,表明它能有效地捕获烷基自由基,与传统的受阻酚类及亚磷酸酯类抗氧剂复配与传统的二元抗氧稳定体系相比,具有添加量少、抗氧性能优等优点.比较了Irganox(R) HP-136(3-芳基-苯并呋喃酮)与传统抗氧剂的抗氧机理,并分析了在聚合物稳定体系中的作用.     

Cu2O-CuAlO2-Cu基金属陶瓷导电性能研究

通过热压技术制备Cu2O-10CuAlO2-xCu金属陶瓷材料，并对其导电性能进行了研究。结果表明，Cu2O-10CuAlO2-xCu在Cu含量超过15wt．％后呈金属导电性。材料的微观结构观察及物理性能测试表明，金属陶瓷材料的电导率不仅取决于材料的金属相含量，还取决于金属相颗粒尺寸和孔隙率的大小。材料中金属相的颗粒尺寸取决于热压工艺参数，随着热压温度的升高而增大，但随热压压力的升高而减小。     

一水合硫酸氢钠催化β-萘甲醚的合成

利用一水合硫酸氢钠催化合成 β 萘甲醚 ,3 6 gβ 萘酚 ,3ml甲醇 ,1 5g一水合硫酸氢钠 ,80℃反应5h ,HPLC分析产率达 78 3%。固体催化剂容易过滤分离。     

湿式氨法脱硫工艺及应用

随着二氧化硫对环境的污染越来越严重,国家环保总局对烟气二氧化硫排放控制严格,烟气脱硫显得日益重要。简单介绍了湿式氨法烟气脱硫技术的工艺流程及实际应用情况。湿式氨法脱硫工艺具有原料易得、脱硫塔不易结垢、不产生废水、副产品硫酸铵可作为农用肥料,减少了对环境的二次污染等特点,是较适合我国国情的烟气脱硫技术。     

Generalized Transfer Subspace Learning Through Low-Rank Constraint

It is expensive to obtain labeled real-world visual data for use in training of supervised algorithms. Therefore, it is valuable to leverage existing databases of labeled data. However, the data in the source databases is often obtained under conditions that differ from those in the new task. Transfer learning provides techniques for transferring learned knowledge from a source domain to a target domain by finding a mapping between them. In this paper, we discuss a method for projecting both source and target data to a generalized subspace where each target sample can be represented by some combination of source samples. By employing a low-rank constraint during this transfer, the structure of source and target domains are preserved. This approach has three benefits. First, good alignment between the domains is ensured through the use of only relevant data in some subspace of the source domain in reconstructing the data in the target domain. Second, the discriminative power of the source domain is naturally passed on to the target domain. Third, noisy information will be filtered out during knowledge transfer. Extensive experiments on synthetic data, and important computer vision problems such as face recognition application and visual domain adaptation for object recognition demonstrate the superiority of the proposed approach over the existing, well-established methods.     

New approach for the preparation of nanoporous polyorganosilicate low‐k films

The distribution of pores and the mechanical properties of materials are the key factors in preparing satisfactory low‐k films. In the present study, a kind of silsesquioxane‐polyethylene glycol (SSQ‐PEG) was synthesized and used as a template to make the distribution of pores more even in the low‐k films. The crosslinking density of films could be adjusted by the sol‐gel of tetramethoxysilane/dimethoxydimethylsilane with various proportions. The porosity of films could also be adjusted with different proportions of pendant PEG chains introduced. A dielectric constant as low as 2.1 had been achieved for nanoporous polyorganosilicate films with good tenacity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1238–1243, 2007     

Cu2O/Cu Cermet as a Candidate Inert Anode for Al Production

Cu₂O/ x Cu ( x =0–25 wt%) cermets were evaluated as a novel partially inert anode for aluminum (Al) production. The physical and mechanical properties, including the compressive strength, flexural strength, thermal expansion coefficient, thermal conductivity, and dc electrical conductivity were tested at room temperature and at temperatures up to 950°C. The coefficient of thermal expansion, compressive strength, flexural strength, thermal conductivity, and electrical conductivity of Cu₂O/Cu cermets increased with increasing Cu content. High-temperature electrical conductivity measurements showed that with increasing temperature, the electrical conductivity increased when the Cu content was below the percolation threshold, while it decreased when the Cu content was above the percolation threshold. A relatively stable CuAlO₂ layer formed on the cermet surface during electrochemical testing, and the corrosion rate of this anode was estimated to be about 1.8–1.9 cm/year in Al production.