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991.
Discharged energy properties of PbO–SrO–Na2O–Nb2O5–SiO2 glass‐ceramics with crystallization time from 1 to 1000 min were investigated by measuring their hysteresis loops (described as quasi‐static measuring method) and pulse‐discharge current‐time curves (described as dynamic measuring method). The results show the same trend for both measuring methods: With the increment of crystallization time, the discharged energy density increases gradually, while the energy efficiency decreases. The highest energy efficiencies were obtained in the sample with crystallization time of 1 min, which are 96.3% and 82.4%, corresponding quasi‐static and dynamic measurement, respectively. The reduction of energy efficiency with crystallization time is attributed to combined effect of ferroelectric polarization and interfacial polarization, and part of the corresponding energy could not release in the pulse‐discharge process.  相似文献   
992.
Bromate by-product formation during ozonation of bromide-containing potable water has aroused widespread concern. In this study, cetylpyridinium chloride was selected to modify two different kinds of granular activated carbon (GAC) to improve their bromate adsorption capacity. The adsorption characteristics of modified GAC were studied by batch and column tests, with results suggesting greatly improved bromate adsorption ability: the saturation capacities for bromate were >7 times for modified GAC than for GAC under the experimental conditions used. This enhancement in adsorptive capacity is likely due to an increase in basic functional groups, because the saturated adsorption capacity of bromate on the GAC is positively correlated with the basic functional groups. The increase of the basic functional groups accelerates OH- dissociation from the GAC surface and protonation of the GAC surface, thus resulting in the enhancement in adsorptive capacity. The modified GAC was relatively immune to the impact of pH change over a broad range. Both the Yoon-Nelson model and the Thomas model fit well the breakthrough curves of bromate adsorbed by modified and unmodified GAC under different conditions. Our results provide insight into the sorption process of bromate onto modified GAC.  相似文献   
993.
Three conjugated polymers, P1–P3, with dithiafulvalene (DTF) as side chains have been synthesized. All polymers have good thermal stabilities. The DTF unit could be oxidized to DTF?+ which was observed from cyclic voltammetry and ultraviolet–visible (UV–vis) spectra, and the oxidation process was independent of the conjugated backbone of the polymer. The strong π–π* transition absorbing band of the three polymers decreases gradually as increasing oxidation, and the resulting DTF?+ species give rise to an additional band at 750–1100 nm, which can be assigned to a distinguishing feature of the cation radical species. Photovoltaic device based on the blend of P2 and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) showed the power conversion efficiency of 1.05% with a fill factor of 42.8%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41508.  相似文献   
994.
Three types of zinc salts, ZnAl2O4, ZnFe2O4, and Zn2SiO4, were prepared by coprecipitation. Potential smoke and toxicity suppression by zinc salts in flame‐retardant polyurethane‐polyisocyanurate foams (FPUR‐PIR) with dimethylmethylphosphonate (DMMP) and tris (2‐chloropropyl) phosphate (TCPP) were investigated. The crystal structure and dispersity of zinc salts in FPUR‐PIR were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Smoke density, flame retardancy, and thermal degradation were studied using smoke density rating (SDR), limiting oxygen index (LOI), the cone calorimeter test, and thermogravimetry coupled with FTIR spectrophotometry (TGA‐FTIR). The results indicated that pure zinc salts were obtained and evenly dispersed on the cell wall of FPUR‐PIR. SDR and the specific extinction area (SEA) were significantly decreased, the time to second heat release rate peak (pk‐HRR) of FRUP‐PIR was delayed after incorporation of the zinc salts; zinc salts partially inhibited phosphorus oxide release into the gas phase, enhanced the condensed phase effect of phosphorus, reduced, and prolonged the release of isocyanate compound and hydrogen cyanide from FRUP‐PIR; due to an increase in the amount of char residues, which indicated the suppression of smoke and toxicity volatiles. ZnFe2O4 resulted in better char formation at the initial degradation stage of FPUR‐PIR, and ZnAl2O4 retained more phosphorus in the solid phase at higher temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41846.  相似文献   
995.
介绍了煤制天然气的技术路线,分析了市场需求、生产成本。煤制天然气与进口SNG、进口增量LNG和进口LPG相比,具有价格优势。按照全生命周期评价方法,分析煤制天然气项目的碳排放和能耗,燃煤发电路线优于常规煤制天然气,应加快研发一步法煤制天然气工艺,提高综合能效。  相似文献   
996.
在低酸度溶液中,以三嵌段非离子表面活性剂P123为模板剂,采用水热合成法制备锡掺杂PHTS催化剂(Sn-PHTS),采用XRD、TEM、N2吸附-脱附、NH3-TPD和FTIR等手段对其进行表征,并考察了Sn-PHTS催化1,4-丁二醇酯化的性能。结果表明,Sn-PHTS催化剂具有有序的六方晶相结构,随着锡含量的增加,其比表面积、孔容、孔径变化较小,酸性逐渐减小;在催化1,4-丁二醇和醋酸的酯化反应中,3Sn-PHTS表现出更高的催化活性,单酯收率达46.8%。  相似文献   
997.
PP改性汽车轮罩专用料的研制   总被引:3,自引:0,他引:3  
通过在聚丙烯中加入EPDM(三元乙丙橡胶)、LDPE,形成三元共混体系,并在体系中加入交联剂、助交联剂、流动性调节剂等助剂及一种较新型的无机填料硅土,可明显改善聚丙烯的冲击性能、加工流动性和尺寸稳定性,使其能够满足生产及性能要求并降低了成本。  相似文献   
998.
以TDI(甲苯二异氰酸酯)、聚酯多元醇、DMPA(二羟甲基丙酸)和硅溶胶等为原料制备了WPU(水性聚氨酯)胶粘剂,考察了硅溶胶掺量对其性能的影响。研究结果表明:随着硅溶胶掺量的不断增加,WPU的平均粒径逐渐增大,胶膜的拉伸强度、硬度、疏水性、耐水性和耐热性等逐渐提高,当w(硅溶胶)=5%(相对于胶粘剂总质量而言)时,复合薄膜的T-剥离强度(为5.0 N/25 mm)和断裂伸长率(为1 658%)相对最大,热稳定性略有提高。  相似文献   
999.
本试验以生鲜鱿鱼为原材料,在常温下研究了盐浓度、pH、麦芽糖醇以及浸泡时间对其保鲜的影响。试验选用了聚酰胺、聚乙烯和聚丙烯3种薄膜对鱿鱼进行包装,每隔3 d对鱿鱼进行观察,测量其得失水情况,并通过感官评定其变质的情况。结果表明:不同保鲜液配比下的鱿鱼失水情况不同,加入盐后会造成鱿鱼失水,而麦芽糖醇对鱿鱼具有保水作用,但糖加入过多会降低保鲜效果,使肉质变松软;浸泡时间也不宜过长;PA薄膜对鱿鱼的保鲜作用更为明显。  相似文献   
1000.
A general protocol for the chemoselectivity‐controlled C C and C S coupling reactions of di(hetero)aryl disulfides with Grignard reagents catalyzed by ferrocene and palladium acetate has been developed. Ferrocene favored the formation of C S coupled products at low temperature, whereas C C bond couplings were favored when palladium acetate was used. All the reactions proceeded with excellent chemoselectivity and in good yields under mild conditions, and a library of molecules with pyridine and pyrimidine scaffolds was produced.

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