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91.
对二聚炔醇化合物DMH的合成、分子结构及缓蚀作用机理进行了论述。因DMH化合物具有独特的分子结构,形成了稳定的络合体系及基团的屏蔽效应,增加了缓蚀被膜厚度及缓蚀体系的化学稳定性,实验证实DMH是酸性介质中的高效缓蚀剂。  相似文献   
92.
Co–BaCO3 catalysts exhibited high catalytic performance for oxidative dehydrogenation of ethane (ODE) using CO2 as oxidant. The maximal formation rate of C2H4 was 0.264 mmol · min−1 · (g · cat.)−1 (48.0% C2H6 conversion, 92.2% C2H4 selectivity, 44.3% C2H4 yield) on 7 wt% Co–BaCO3 catalyst at 650 °C and 6000 ml. (g · cat.)−1. h−1. Co–BaCO3 catalysts were comparatively characterized by XRF, N2 isotherm adsorption-desorption, XRD, H2-TPR and LRs. It was found that Co4+–O species were active sites on these catalysts in ODE with CO2. The redox cycle of Co–O species played an important role on the catalytic performance of Co–BaCO3 catalysts. On the other hand, the co-operation of BaCO3 and BaCoO3 was considered to be one of possible reasons for the high catalytic activity of these catalysts.  相似文献   
93.
The effect of TiO2 nanoparticles for sun-weathering protection of UV-cured coatings is investigated. TiO2 is either introduced in the form of nanoparticles in the photocurable formulations or generated in situ via sol–gel process. Cured films containing comparable amounts of TiO2 were weathered for 800 h under UV irradiation and compared with free-TiO2 coating. The TiO2 presence induces a clear lower mass loss decrease during weathering as well as a lower gel content decrease. The TiO2 screen effect is also confirmed by a lower alkyl-band reduction monitored by FT-IR during weathering. The TiO2 generated in situ via sol–gel gives rise to transparent coatings without interfering with photopolymerization process and therefore without compromising UV-cured film properties.  相似文献   
94.
The effect of Mg-doping and Li overstoichiometry on the structural stability of LiCoO2 powders has been investigated with emphasis to voltammetric properties. Microparticle cyclic voltammetry (CV) conducted in caustic NaOH to best simulate a non-aqueous electrolyte shows a marked improvement of the structure stability of doped LiCoO2. In contrast to the unsubstituted LiCoO2 sample which shows voltammetric peaks associated to the well-known two-phase domain and monoclinic distortion reactions, in Li1.08Mg0.06CoO2, LiMg0.06CoO2 and Li1.08CoO2 samples these peaks are strongly suppressed providing direct evidence for the existence of a stable solid solution with negligible phase transitions in the reversible intercalation region (3.8-4.2 V vs. Li) as well as in the overcharged region. The effect is higher with Mg-doping, irrespective of the Li overstoichiometry. However, the concomitant presence of Mg and Li excess in the structure is important for obtaining small particle sizes. Since Mg-doping induces a quasi metallic behavior in the samples, whereas the Li excess may provide an higher initial capacity, it is suggested that the Li1.08Mg0.06CoO2 composition may be of interest as positive cathode for advanced Li-ion batteries.  相似文献   
95.
We investigated cues that mediate the aggregation behavior of immature pentatomid bugs by using nymphs of six different pentatomid bug species (Nezara viridula, Acrosternum hilare, Chlorochroa ligata, Chlorochroa sayi, Thyanta pallidovirens, and Euschistus conspersus). When first instars of any two species were put together in a Petri dish, they readily formed heterospecific aggregations similar to their natural conspecific aggregations. The chemical profiles of first and second instar nymphs of each species were determined by solvent extraction with pentane, followed by GC-MS analysis. Immature bugs of the different species had some compounds in common, and some that were more species specific. Within a species, there were distinct differences in the profiles of compounds extracted from first and second instars. Bugs did not aggregate around untreated polysulfone beads (1 mm diam) that were glued together in groups approximating bug egg masses, suggesting that tactile cues alone were insufficient to induce aggregation. Furthermore, when tested over a range of doses, groups of polysulfone beads treated with crude whole-body extracts of bugs did not induce or maintain aggregations. However, first instar N. viridula nymphs did respond to beads treated with two of the three major components of bug extracts. 4-Oxo-(E)-2-decenal induced significant aggregations at two doses, whereas tridecane, the major component in extracts from all six species, did not, and (E)-2-decenal was repellent. The repellence of (E)-2-decenal may explain why we and previous researchers were unable to induce aggregations of first instar N. viridula using whole-body extracts.  相似文献   
96.
纳米稀土复合固体超强酸催化合成乙酸苄酯   总被引:4,自引:0,他引:4  
杨义文  李蕾  陈慧宗 《化学试剂》2006,28(11):665-667
采用共沉淀法制备了纳米稀土复合固体超强酸SO4^2-/ZrO2-2%Nd2O3催化剂,电镜分析表明,催化剂颗粒直径在25nm左右,比表面积测定:71.03m^2/g。酸强度-12.70〈Ho〈-11.99。并对合成乙酸苄酯的最佳反应条件进行了研究。研究表明:当苯甲醇与乙酸的物质的量比为1:2,反应时间为5h,反应温度为120℃,催化剂用量为6%苯甲醇的质量时,酯化率可达92.04%。研究发现,该催化剂可重复使用并可活化再生。  相似文献   
97.
Microcellular foaming of biodegradable Bionolle in supercritical CO2 has been produced. The effects of a series of variable factors, such as saturation temperature, saturation pressure, and depressurization time and step on the foam structures and density, were studied through measurement of density and SEM observation. The experimental results show that higher saturation temperatures lead to an increase in bulk densities; and different depressurization time and step result in different product cell morphology. In addition, at some saturation temperature, the orientation of the cells can be found in the product morphology. XRD experimental results show that the foaming treatment with SC CO2 increased the crystallinity of Bionolle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2901–2906, 2006  相似文献   
98.
On basis of adopting polygeneration systems for power and alternative fuels,capturing CO2 with near zero energy penalties,and storing CO2 on sites,a new kind of Energy Network can integrate energy utilization,CO2 capture,transportation and storage synthetically.Techno-economic analysis of this solution focusing on Inner Mongolia and the Yangtze River Delta districts had been carried with comparison to the chain method for energy utilization and CO2 sequestration.This solution can save 21.5% of energy,and re...  相似文献   
99.
100.
SnO2 electrodes have many advantages in the degradation of toxic or bio-refractory organic wastewater,and SnO2 is a kind of anode material which has the potential to be widely used.Electrocatalytic effi-ciency and service life of Ti\SnO2 electrodes are key factors that can influence its applications.In order to enhance the electrocatalytic characteristics of Ti\SnO2 electrodes,a type of electrocatalytic electrode with nanocoating was prepared by direct current(DC)electrodeposition method and thermal oxidati...  相似文献   
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