Magnetic Memory Effect of Nanocomposites

The magnetic memory effect (MME) is the ability of magneto‐sensitive materials to remember the magnetic field strength (H_def), at which they were deformed recently. They respond close to H_def either by recovering their initial shape at a switching magnetic field strength H_sw under stress‐free conditions or by building up stress with a peak maximum at H_σ,max under constant strain conditions. This paper explores whether such a MME can be created for polymer‐based nanocomposites. The concept is based on temperature‐memory polymers (TMP) as matrix, in which silica coated iron(III)oxide nanoparticles (mNP) are dispersed. The MME was explored in a cyclic magneto‐mechanical test, in which the nanocomposite sample was elongated to ?_m while being exposed to an alternating magnetic field at H_def. The magnetic memory was read out by determining H_σ,max or H_sw. A linear correlation between H_σ,max (or H_sw) and H_def in a range from 15 to 23 kA m^?1 at a fixed frequency of f = 258 kHz is observed and demonstrates the excellent magnetic memory properties of the investigated nanocomposites containing either crystallizable or amorphous, vitrifiable domains as controlling units. The deformation ?m at H_def can be fixed with an accuracy of more than 72% and the initial shape can be recovered almost completely by more than 86%. The MME allows the design of magnetically programmable devices such as switches or mechanical manipulators.     

ε-CL-20不同晶面与PVA、PEG复合物的MD模拟

为探讨和比较在ε-CL-20(六硝基六氮杂异伍兹烷)(001)、(110)和(020)晶面上的ε-CL-20/PVA(聚乙烯醇)与ε-CL-20/PEG(聚乙二醇)复合物的稳定性和力学性能,在COMPASS力场下,对ε-CL-20/PVA与ε-CL-20/PEG进行了常温常压分子动力学(MD)模拟研究。求得其内聚能密度(CED),结合能(E_(bind))和弹性参数(拉伸模量E、剪切模量G、体积模量K、泊松比ν和柯西压C_(12)-C_(44))。结果表明,在相同晶面上,ε-CL-20/PEG的CED比ε-CL-20/PVA的大,表明前者稳定性优于后者。对于同一复合物,其CED排序为(020)(001)(110)。在相同晶面上,PEG与晶面的E_(bind)比PVA的大。对同一复合物,其E_(bind)大小次序为(001)(110)(020)。依据泊松比和K/G值,ε-CL-20/PEG的弹性和延展性均优于ε-CL-20/PVA。     

三元乙丙材料粘超弹本构模型研究

利用等速拉伸和拉伸-回复实验研究三元乙丙（EPDM）包覆层材料的力学特性,提出采用有限变形条件下的超弹本构模型及线粘弹性本构理论相结合的方法建立一种粘超弹本构模型,在此基础上进一步研究模型参数的获取方法。研究结果表明：该材料具有典型的超弹性力学行为特征,并呈现出明显的率相关效应;所建立的粘超弹本构模型能够较好地描述该材料的单轴力学行为,在一定程度上可对使用该包覆层材料的固体火箭发动机的结构完整性分析提供理论参考。     

优化生产运行，实现乙烯装置节能降耗

近年来中国石化广州分公司乙烯的能耗水平逐年下降,综合能耗从2003年的725．04kg标油/t下降至2005年的682．48kg标油/t。主要措施为：①通过回收火炬气、应用低压甲烷烧嘴等措施对燃料气系统进行优化。同时优化了炼油区和化工区的燃料气配置,减少了燃料气损失;②通过改由自备热电站输送蒸汽、减少蒸汽放空、透平与电泵切换操作等措施对蒸汽系统进行了平衡和优化,减少了蒸汽损耗;③优化了裂解原料,提高了乙烯收率。提出了进～步节能降耗的设想。     

Perovskite-type oxides La1−xSrxMnO3 for cathode catalysts in direct ethylene glycol alkaline fuel cells

Carbon-supported La_1−xSr_xMnO₃ (LSM/C) was prepared by reversible homogeneous precipitation method, and its catalytic activities for oxygen reduction under the existence of ethylene glycol (EG) were investigated by using rotating disk electrode. LSM/C exhibited the high activity for oxygen reduction irrespective with the presence of EG, indicating that EG is not oxidized by LSM/C at the cathode side in the present system. Consequently, LSM/C can serve as a cathode catalyst in alkaline direct alcohol fuel cells with no crossover problem. Performance test for fuel cells operation also supported these results and showed cathodic polarization curves were not affected by the concentration of EG supplied to anode even at 5 mol dm⁻³.     

新型碳三馏分液相加氢催化剂PEC-31的工业应用

介绍了中国石油石油化工研究院自主开发的新型碳三馏分加氢催化剂PEC-31在中国石油兰州石化公司24万t/a乙烯装置稳定运行超过200 d的首次工业应用情况。结果表明:在加氢反应器入口碳三馏分物料中的甲基乙炔（MA）和丙二烯（PD）混合物（MAPD）体积分数为 2.0%～3.5%,氢气与丙炔&丙二烯的摩尔比为1.00～1.50,反应器入口温度为32 ℃,碳三馏分物料的液相体积空速为40～45 h-1的工况下,PEC-31催化剂作用下的MAPD转化率、丙烯选择性相应均值分别为98.50%,80.10%。     

The direct,one-step process for synthesis of dimethyl ether from syngas. III. DME as a chemical feedstock

In Parts I & II of this Series, we illustrated the process research studies on a new, trendsetting indirect syngas conversion process, the direct, one-step LPDME^tm process, which is now a shining example of “dual catalysis” or “cooperative/adaptive” catalysis and also of thermodynamic/kinetic coupling in series-parallel reactions.

In this part III, we take a look at several processes on the research and pilot scale that employ methanol and DME as chemical feedstocks for further conversion to value-added chemicals. A most rational and cogent argument for the use of DME as a feedstock is that the unit production cost of DME from the direct, one-step DME processes, most notably the LPDME^tm process, can be lower than methanol (from LPMeOH^tm), on a methanol-equivalent basis. DME also has inherently more benign physical and chemical properties, contains 1 less mole of water, and results in a substantially similar product distribution, as methanol, for the methanol-to-gasoline (MTG) and methanol-to-olefins (MTO) process. DME can also be converted to several other important chemicals; some of these include dimethoxymethane, dimethoxyethane, methylal, formaldehyde, acetic acid, methyl acetate, and polyoxymethylene ethers. In this report, we offer a critical assessment of the current status of these processes and a projected path to commercialization. Considering the trendsetting and impactful nature of DME as a chemical entity and as a chemical feedstock, along with its “free” cost, we are of the opinion that the future of DME, and of its chemical conversions, as so-called “DME economy”, is very bright.     

酸催化二甘醇脱水环化反应研究

以硫酸、磷钨酸、ZRP-5分子筛为催化剂,研究了二甘醇(DEG)脱水环化的反应规律。结果表明,DEG发生分子内脱水环化反应,生成1,4-二氧六环(DOX),DEG分子间脱水不仅可以生成四甘醇、六甘醇等,同时可生成三甘醇、五甘醇等一系列的多甘醇(PEG)。不仅DEG可以脱水环化生成DOX,在反应中生成的PEG也同样可以进行生成DOX的反应。对于二甘醇(DEG)脱水环化反应,硫酸是性能优良的催化剂,反应可以在较低的温度下进行,馏出产物中DOX选择性大于95％。     

环氧乙烷合成乙二醇的研究进展

介绍了环氧乙烷合成乙二醇的主要生产方法，包括以壳牌、联碳化学公司以及Halcon—SD公司为代表的环氧乙烷直接水合法，环氧乙烷催化水合法和碳酸乙烯酯法，后两种乙二醇生产方法是目前国内外研究开发的热点。催化剂体系是催化水合法工艺的关键，重点介绍了国内外各主要公司对催化剂体系的研究进展及使用效果；碳酸乙烯酯法分为乙二醇和碳酸二甲酯联产法以及碳酸乙烯酯水解法，详细介绍了国内外各主要公司对该技术的研究进展，包括工艺流程、催化剂体系等方面。将3种乙二醇生产方法进行技术经济比较，结果表明，催化水合法和碳酸乙烯酯法在原料消耗和能耗方面占优势。并对我国乙二醇生产工艺技术提出建议。     

国内外丁二烯抽提技术的比较

根据广州石化60万t/a乙烯改扩建的裂解C4产量及现有加工能力，需要新建一套13．5万t/a丁二烯抽提装置。通过对国内外的二甲基甲酰胺法、乙腈法、N-甲基吡咯烷酮法工艺路线进行技术比较，为分公司乙烯改扩建技术、商务谈判和确定最终的专利技术提供依据。