正癸烷脱氢生成直链单烯烃的热力学分析

较详细地计算了正癸烷脱氢生成各直链单烯烃主反应的热力学平衡参数,并对产物分布以及温度,压力,氢／烃和惰性气／烃摩尔比对平衡的影响地进行了分析,为工业化操作及内烯烃的开发利用提供了一定的理论依据.     

多速率码流同步复接方案设计与实现

采用正／0／负码速调整方法,设计了一种多速率码流同步复接的帧结构方案,并对其相关性能及复接／分接的实现方法进行了详细介绍。     

19% efficient n‐type Czochralski silicon solar cells with screen‐printed aluminium‐alloyed rear emitter

High and stable lifetimes recently reported for n‐type silicon materials are an important and promising prerequisite for innovative solar cells. To exploit the advantages of the excellent electrical properties of n‐type Si wafers for manufacturing simple and industrially feasible high‐efficiency solar cells, we focus on back junction n⁺np⁺ solar cells featuring an easy‐to‐fabricate full‐area screen‐printed aluminium‐alloyed rear p⁺ emitter. Independently confirmed record‐high efficiencies have been achieved on n‐type phosphorus‐doped Czochralski‐grown silicon material: 18·9% for laboratory‐type n⁺np⁺ solar cells (4 cm²) with shadow‐mask evaporated front contact grid and 17·0% for front and rear screen‐printed industrial‐type cells (100 cm²). The electrical cell parameters were found to be perfectly stable under illumination. Copyright © 2006 John Wiley & Sons, Ltd.     

PCA过程监测方法的故障检测行为分析

通过分别导出T2 和SPE统计量均值与过程数据统计参数之间的关系 ,分析了影响主元分析 (PCA)检测行为的因素以及工况变化与故障在PCA下的不同被检测行为 ,利用双效蒸发过程的仿真监测验证了获得的结果 ,指出了通常关于PCA检测行为的一些不准确的结论     

Modeling, analysis and prediction of neutron emission spectra from acoustic cavitation bubble fusion experiments

Self-nucleated and external neutron nucleated acoustic (bubble fusion) cavitation experiments have been modeled and analyzed for neutron spectral characteristics at the detector locations for all separate successful published bubble fusion studies. Our predictive approach was first calibrated and validated against the measured neutron spectrum emitted from a spontaneous fission source (²⁵²Cf), from a Pu–Be source and from an accelerator-based monoenergetic 14.1 MeV neutrons, respectively. Three-dimensional Monte-Carlo neutron transport calculations of 2.45 MeV neutrons from imploding bubbles were conducted, using the well-known MCNP5 transport code, for the published original experimental studies of Taleyarkhan et al. [Taleyarkhan, et al., 2002. Science 295, 1868; Taleyarkhan, et al., 2004. Phys. Rev. E 69, 036109; Taleyarkhan, et al., 2006a. PRL 96, 034301; Taleyarkhan, et al., 2006b. PRL 97, 149404] as also the successful confirmation studies of Xu et al. [Xu, Y., et al., 2005. Nuclear Eng. Des. 235, 1317–1324], Forringer et al. [Forringer, E., et al., 2006a. Transaction on American Nuclear Society Conference, vol. 95, Albuquerque, NM, USA, November 15, 2006, p. 736; Forringer, E., et al., 2006b. Proceedings of the International Conference on Fusion Energy, Albuquerque, NM, USA, November 14, 2006] and Bugg [Bugg, W., 2006. Report on Activities on June 2006 Visit, Report to Purdue University, June 9, 2006]. NE-213 liquid scintillation (LS) detector response was calculated using the SCINFUL code. These were cross-checked using a separate independent approach involving weighting and convoluting MCNP5 predictions with published experimentally measured NE-213 detector neutron response curves for monoenergetic neutrons at various energies. The impact of neutron pulse-pileup during bubble fusion was verified and estimated with pulsed neutron generator based experiments and first-principle calculations. Results of modeling-cum-experimentation were found to be consistent with published experimentally observed neutron spectra for 2.45 MeV neutron emissions during acoustic cavitation (bubble) fusion experimental conditions with and without ice-pack (thermal) shielding. Calculated neutron spectra with the inclusion of ice-pack shielding are consistent with the published spectra from experiments of Taleyarkhan et al. [Taleyarkhan, et al., 2006a. PRL 96, 034301] and Xu et al. [Xu, Y., et al., 2005. Nuclear Eng. Des. 235, 1317–1324] where ice-pack shielding was present, whereas without ice-pack shielding the calculated neutron spectrum is consistent with the experimentally observed neutron spectra of Taleyarkhan et al. [Taleyarkhan, et al., 2002. Science 295, 1868; Taleyarkhan, et al., 2004. Phys. Rev. E 69, 036109] and Forringer et al. [Forringer, E., et al., 2006a. Transaction on American Nuclear Society Conference, vol. 95, Albuquerque, NM, USA, November 15, 2006, p. 736; Forringer, E., et al., 2006b. Proceedings of the International Conference on Fusion Energy, Albuquerque, NM, USA, November 14, 2006] and also that from GEANT computer code [Agostinelli, S., et al., 2003. Nuclear Instrum. Methods Phys. Res. A 506, 250–303] predictions [Naranjo, B., 2006. PRL 97 (October), 149403] in which ice shielding was also absent.The results of this archive confirm for the record that the confusion and controversies caused from past reports [Reich, E., 2006. Nature (March) 060306. news@nature.com; Naranjo, B., 2006. PRL, 97 (October) 149403] have resulted from their neglect of important details of bubble fusion experiments. Results from this paper demonstrate that ice-pack shielding between the detector and the fusion neutron source, gamma photon leakage and neutron pulse-pileup due to picosecond duration neutron pulse emission effects play important roles in affecting the spectra of neutrons from acoustic inertial confinement thermonuclear fusion experiments.     

The concentration and distribution of essential elements in brown rice associated with the polishing rate: Use of ICP-AES and Micro-PIXE

The concentration and distribution of essential elements in brown rice grains (Oryza sativa L. var. japonica) associated with the polishing rate was determined. Rice samples were collected in Japan and polished to 5%, 10%, 15% and 20% loss of the total weight of brown rice. Concentrations of eight essential elements (P, K, Ca, Mg, Cu, Fe, Mn and Zn) were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), and distributions of the elements in a single grain were visualized as elemental distribution maps of a cross section by micro particle induced X-ray emission (Micro-PIXE) analysis. Results of ICP-AES analysis indicated that in rice which polished from 0% to 10% loss of weight, there were three patterns in the P/B ratio, which is the mean concentration of an element in polished rice divided by that of the element in the brown rice: no change (Cu and Zn), a gradual decrease (P, Mg, Mn and Fe), and a decrease after a constant phase (Ca and K). There was no remarkable change of the P/B ratio in rice grains which polished from 10% to 20% loss of weight. Micro-PIXE analysis images showed that P, K, Ca, Mg, Fe and Mn were present in large amounts in the surface layer (approx. <200 μm thickness) of brown rice. Two sub-layers were mainly recognized in the grain surface layer in the elemental distribution maps of a cross section. The first sub-layer was approximately 130-170 μm thick. The second sub-layer was approximately 20-50 μm thick, and the primary part of the grain (endosperm cells and starch granules) was under it. The images showed Cu and Zn were uniformity distributed in brown rice, and their concentrations of polished rice were not affected by the polishing rate. Although ICP-AES measurements could not provide the detail structure of the surface layer of the rice grains, the trend of concentration of the elements generally agreed with the elemental distribution maps obtained Micro-PIXE analysis.     

氰乙酸正丁酯合成的研究

以氰乙酸乙酯与正丁醇为原料 ,采用酯交换法合成氰乙酸正丁酯。考察了反应时间、原料配比、反应温度、催化剂种类及用量等对反应产率的影响。并对反应结果进行定量分析 ,采用红外光谱对合成产物进行结构确定。指出了合成氰乙酸正丁酯较佳的工艺路线     

双芯光纤中孤子传输与耦合特性研究

利用自伴算符方法,通过耦合非线性薛定格方程分析了双芯光纤中孤子的传输与耦合特性。研究结果表明：孤子脉冲在两纤芯间的耦合特性与注入的孤子振幅有密切关系,耦合特性表现为周期性、非完全周期性和完全非周期性的能量变换;孤子脉冲在两纤芯间的传输特性与注入的两孤子间相对相位有密切关系。     

清洁生产的回顾与展望

介绍了清洁生产的概念及其来源,探讨了实施清洁生产的主要途径和清洁生产的发展趋势。     

2,4-二氯氟苯合成工艺研究

由对二氯苯经三步反应合成了 2 ,4 二氯氟苯。用硝硫混酸硝化对二氯苯生成 2 ,5 二氯硝基苯 ,收率 98%以上。后者在环丁砜中与氟化钾反应 ,得 2 氟 5 氯硝基苯 ,收率 6 8% (由GC测定 )。 2 氟 5 氯硝基苯在偶氮二异丁腈存在下与氯气发生连续脱硝基氯化反应 ,得目标化合物 2 ,4 二氯氟苯 ,收率94%。该合成路线避免了氯苯路线以爆炸性的二硝基氯苯为中间体的缺陷 ,安全性较好。